Slashdot is powered by your submissions, so send in your scoop


Forgot your password?

Slashdot videos: Now with more Slashdot!

  • View

  • Discuss

  • Share

We've improved Slashdot's video section; now you can view our video interviews, product close-ups and site visits with all the usual Slashdot options to comment, share, etc. No more walled garden! It's a work in progress -- we hope you'll check it out (Learn more about the recent updates).

The Internet Cellphones Communications Technology

Cell Phone Jamming Devices Enjoy an Increase In Popularity 805

Posted by timothy
from the can-you-hear-me-carrier-lost dept.
rullywowr writes "A story run by local new NBC10 of Philadelphia last Friday illuminated the fact that this particular rider of the pubilc bus system is packing a cell phone jammer and is not afraid to use it. Going by the name of 'Eric,' whenever he sees someone being 'rude' on the bus and talking loudly on their cell phone, he screws the antenna on and flips the power switch. Regardless of the steep civil penalites levied by the FCC (up to $16,000 USD), many (such as 'Eric') are still interested by these devices which can be bought on the internet for $40 to over $1000. Opponents of these devices say that not only do they interfere with mobile phones, they often can interfere with 'behind the scenes' communication, Wi-Fi, etc. Despite being illegal, TFA points out that they are readily available on the internet (what else is new?). Do you have an instance where you experienced the positive (or negative) effects of a cell phone jammer?"
This discussion has been archived. No new comments can be posted.

Cell Phone Jamming Devices Enjoy an Increase In Popularity

Comments Filter:
  • by darjen (879890) on Tuesday March 06, 2012 @12:49PM (#39262335)

    If someone was doing this while I commute to work, and I wasn't able to use my 3g connection, I would be pissed.

  • ladyada (Score:3, Interesting)

    by AtomicAdam (959649) on Tuesday March 06, 2012 @12:51PM (#39262371)
    I saw designs on Limor fried's Site years ago that she made for her thesis I believe. It's a good read. Either way it's funny how long these things took to become popular [] TFL for anyone who can't google
  • by christoofar (451967) on Tuesday March 06, 2012 @12:51PM (#39262377)

    I can tell you with what joy it is to live in a city where listening to B-grade hip hop music on tinny cell phone speakers is the norm. That you can't stop, but when I have to be subjected to a very lengthy screaming match between baby-momma and her baby-daddy, with a push of a button I can cut that nonsense out. If you want to do that nonsense, then get off the train at the next stop and have your bitch fest there.

    I can't do much about the panhandlers that pass through the trains hocking bootleg DVDs, scented oils or begging for quarters, but I CAN do something about the chaff of society who can't keep their Jerry Springer drama to themselves, and so I shut them down with a jammer. If an emergency crops up, I turn the device off.

  • by JustAnotherIdiot (1980292) on Tuesday March 06, 2012 @12:53PM (#39262407)
    Movie theaters come to mind at first, granted I don't go all that often, but still.
    They always have that announcement that everyone ignores to turn off your phone
    This way they don't have to ask, they just stop working.
    If there's some sort of emergency, I'm sure the theaters have a wired phone somewhere they can use quickly.
  • Re:I approve (Score:4, Interesting)

    by danomac (1032160) on Tuesday March 06, 2012 @12:53PM (#39262413)

    I generally don't use my cell phone where I think you shouldn't. This includes restaurants, theatres, public transit, etc.

    If it rings, I may look at it to see who is calling. I won't answer it and sometimes just leave the phone on vibrate.

    I don't understand why people think they must be able to talk on the phone everywhere. I find it more annoying now with a cell phone, as people pretty much expect you to answer it as they're calling you directly and not your house.

  • by John Napkintosh (140126) on Tuesday March 06, 2012 @12:57PM (#39262479) Homepage

    Audio pollution isn't something you get to have control over. Feel free to tell someone they're being annoying, but sometimes you're just going to have to deal with someone talking on their phone in a way that annoys you. If it's not that, it will be someone talking loudly to the person standing next to them. Or a person honking their horn to much or for no reason. Or someone with their cell phone's speaker turned on as they listen to MP3s. Or jackhammers or machinery or the buzz of a refrigerator. How are you going to jam that?

  • by Matt_Bennett (79107) on Tuesday March 06, 2012 @12:59PM (#39262509) Homepage Journal

    I've seen the effect upon drivers talking on their phones while driving. While talking on the phone, their speed is erratic and inconsistent, they wander around their lane. Once in range of such a device, they look at their phone for a second or two, put the phone down, and start to pay attention to the machine that they are controlling. Once their conversation ends, they have become much more responsible drivers, aware of those that are sharing the road with them.

    Just an observation. I understand that jammers are illegal for very good reasons, and their abuse can lead to much more harm than good.

  • Re:I approve (Score:5, Interesting)

    by DigiShaman (671371) on Tuesday March 06, 2012 @01:00PM (#39262519) Homepage

    My proposal for movie theaters and restaurants. By default, these facilities should have cell phone jamming technology enabled with a clear sign stating as such. Also, the sign will point to a red painted receiver designated for 911 use only. Think of the emergency concept of a fire extinguisher and apply that to wired phones and you get the idea.

  • Up the penalties (Score:3, Interesting)

    by Anonymous Coward on Tuesday March 06, 2012 @01:01PM (#39262545)

    Obviously the potential penalties are not high enough. This is naked vigilanteism and should be stopped cold and hard.

    YOU don't have RIGHT to interfere in MY liberty. If I'm being an asshole and talking loudly on the bus, then call a cop. That's how law and order works.

    What's next, you firing an EMP gun at my house because my lights are interfering with your desire to stargaze?

    Are you going to poison my dog because he barks too much or shits too much?

    This one's a real slippery slope people.

  • Re:I approve (Score:5, Interesting)

    by tlhIngan (30335) <<slashdot> <at> <>> on Tuesday March 06, 2012 @01:09PM (#39262729)

    I generally don't use my cell phone where I think you shouldn't. This includes restaurants, theatres, public transit, etc.

    If it rings, I may look at it to see who is calling. I won't answer it and sometimes just leave the phone on vibrate.

    I don't understand why people think they must be able to talk on the phone everywhere. I find it more annoying now with a cell phone, as people pretty much expect you to answer it as they're calling you directly and not your house.

    I do it in degrees. If it's a casual group of my friends, I will excuse myself and leave the group to take the call outside, so I don't subject them to my conversation, then return back when I'm done.

    If it's a more formal event, phone's on vibrate and only in dire emergencies would I answer. And even then I'd politely excuse myself from the group.

    And texting/emailing is a no-no unless there's a very good reason - all live conversations have priority over a texted one except in emergencies. Surfing the web is limited to only if it's something the group requires (e.g., resolving an argument or looking something up).

    And no, I don't have voicemail.

    Anyhow, yes it's illegal, but if you do it right, it can be hard to detect (the only way to track a jammer is to triangulate its position - there's no magic CSI GPS beacon). Perhaps when the bus reaches a certain intersection implying a dead spot for signals, and never more than neessary to break the connection (should just be a few seconds).

    I suppose the bigger question is - why have manners deteriorated to the point that the general public feels it's necessary to take technological measures to fix social problems? The purchase and use of jammers is just a symptom of an underlying societal problem

  • by Jawnn (445279) on Tuesday March 06, 2012 @01:14PM (#39262805)
    True, we do not have the right to not be annoyed, in public places. The bus/train arguably qualifies as "public", but I will never understand why, for example, restaurants and movie theaters (most of them) tolerate behavior this is, to say the least, boorish and disruptive to the experience of the other customers. Just once, I'd love to see the dumb-ass at the next table have her meal removed and shown the door, with the explanation that manners count and those without them are unwelcome.
  • Re:I approve (Score:5, Interesting)

    by Christopher_G_Lewis (260977) on Tuesday March 06, 2012 @01:17PM (#39262877) Homepage

    Actually, in Chicago it's against the law to sleep on public transportation, but not illegal to talk on a cell phone (at a resonable volume).

    Best quote I ever heard on the train: "Honey, I've got to hang up - everyone's looking at me like I'm 'That Guy' ". Got quite a laugh out of the other riders.

  • by christoofar (451967) on Tuesday March 06, 2012 @01:19PM (#39262907)

    Considering how many people in Philadelphia have criminal convictions, I don't feel like playing therapist to baby-momma-drama. It's easier to just shut them down. If you want your bars back, then step off the subway and talk on the platform and get on the next train.

  • by peragrin (659227) on Tuesday March 06, 2012 @01:23PM (#39262973)

    Thaat depends
    Are you talking loud enough to be clearly heard the length of said bus. It is about volume more thann anything. Talk softly and no one is likely to care.

    For me i would put a jammer with a momentary switch so it only jams while being depressed. 5 seconds is enough to cut a call. And it looks like the provider dropped it.

  • by Hoi Polloi (522990) on Tuesday March 06, 2012 @01:43PM (#39263381) Journal

    Now if only they could invent a jammer for people who have their headphones cranked up to 11 until I swear their ears must be bleeding. If it is loud for me sitting next to you I can only imagine what must be left of your hearing.

  • Re:I approve (Score:5, Interesting)

    by mswope (242988) on Tuesday March 06, 2012 @02:11PM (#39263915) Journal

    Or, install an indoor repeater with a dummy load on the outdoor antenna port. The signal from the cell phone will be "captured" by the repeater, but the user won't be able to get a channel to place a call.

  • Re:I approve (Score:5, Interesting)

    by GameboyRMH (1153867) <> on Tuesday March 06, 2012 @02:23PM (#39264157) Journal

    I don't use Facebook. I barely use my phone actually, so you'd think I'd be in the bitter neckbeard camp, but I'm not a horrible selfish sociopath.

    Also I guess your dad is rich so you've never had to hunt for a job. One missed call CAN fuck you up.

  • Re:I approve (Score:3, Interesting)

    by mvdwege (243851) <> on Tuesday March 06, 2012 @02:32PM (#39264337) Homepage Journal

    An who the hell are you to determine when someone can use their phone?

    I'm a member of the public who doesn't want to spend his entire time in a public space listening to someone else's noise. A short, or low-volume conversation is one thing, but you are in public, among other people, and your right to do stops at their right to not be bothered by you.

    Personally, I hope you run into someone with a short temper who rams that cellphone up your nostrils.


  • by wierd_w (1375923) on Tuesday March 06, 2012 @07:17PM (#39268011)

    Cellphone jamming does not have to be dickish to everyone else around it.

    Here is how I personally would make a cellphone jammer:

    Take an ordinary quad band cellphone, preferably an android one with a well documented radio, with a rear facing camera, and a custom rom image running with root.

    On the phone is the "jam this bastard!" Application, which I will have written myself. What it does is put the phone into promiscuous mode to capture datagrams not directed at it, and take signal to noise ratio measurements, along with a camera distance estimate from the rear facing camera. Using some inverse cube rule math, and some fuzzy metrics from the camera, it identifies the "bastard" you are aiming the phone at. You simply pretend you are texting away.

    Once it identifies the "bastard", and their uuid (iemi, ssid, mac, whatever the network uses), and the tower+protocol used, it starts spoofing RST datagrams from the tower, sent as unicasts over the cellular band being used by the "bastard", with headers indicating that it is for the bastard's handset. The rate of injection is configurable.

    This causes the "bastard" to lose connection with the tower as his handset obeys the connection reset command. A combination of this and some clever and fast spoofing on the part of the jamming phone to impersonate the jammed handset to send the "hang up" signal to the tower, will force a targetted dropped calls. At least in theory.

    It would not impact any other cellular users, since it would use spoofed unicasts.

    In the event that it can't directly interface with the target network, it would use the camera for range finding, and look for "noise".
    It would then use a combination of the internal antennas broadcasting raw bit patterns to poison a specific noise source. (Say, using a multiplexed 2.4ghz wifi signal with an 800mhz signal to create a psuedo-broadcast at some other frequency via partial wave reinforcement, done using timed broadcasts of a user data pattern.)

    The partial wave reinforcement to create the false effective signal would have a radically short range. It might interfere with other nearby devices, but would be quickly and effectively attenuated by environmental obstacles.

    (Basically, you create a "beat" frequency emission using two frequencies on either side of the target frequency. The overlap of the two signals creates a 'false', or "beat" frequency in the desired band. If either of the source emissions falls off or gets deflected/reflected, the resulting beat freq will not be in the target band.)

    This means the signal would still not leave the bus.

    This might not force a disconnect, but would degrade QoS, and might improve the chances of a natural disconnect, especially if the bus is moving, since it could disrupt tower handoff.

    (The second method is for, eg, a verizon smartphone using "bastard", and a quadband T-mo using jammer. The jammer cannot see the raw data traffic on verizon's spectrum, since the phone antenna is not able to pick it up. No radio emission is completely discrete, especially with multipath interferences and other randomizing sources of attenuation, so communications on that foreign band should be detectable as noise on the native band from the local environmental attenuation. This is similar to an att gsm phone making a home stereo buzz. The phone is not really broadcasting on such a low frequency, the signal just attenuates there/causes a signal induction, creating noise.)

    In europe, where practically everyone uses gsm, the android smartphone based jamming app would be surgical and effective. In NA, where there is cdma and gsm, the dirty second option is needed.

    Granted, very few handsets have radios with such capabilities, or are sufficiently well documented publicly to bastardize them for this purpose.

    In the first case, anybody else on the bus will be totally unimpacted by the DoS exploit.

    In the second case, some nearby (within maybe 2 to 5 meters) people might be effected, but only if th

A hacker does for love what others would not do for money.