An anonymous reader writes: Ars summarizes a new report into the common practice of ISPs implementing data caps, ostensibly to keep their network traffic under control. The report found a much simpler reason: money. Quoting: 'The truly curious thing about the entire debate has been the way in which caps have mostly remained steady for years, even as the price of delivering data has plunged. For example, paying for transit capacity at a New York Internet exchange costs 50 percent less now than it did just one year ago, and many major ISPs aren't paying at all to exchange data thanks to peering. So why don't prices seem to fall? ... The authors of the new paper contend that all explanations are more or less hand-waving designed to disguise the fact that Internet providers are now raking in huge—in some cases, record—profit margins, without even the expense of building new networks. ...While Internet users have to endure a ceaseless litany of complaints about a "spectrum crunch" and an "exaflood" of data from which ISPs are suffering, most wireline ISPs are actually investing less money in their network as a percentage of revenue, and wireless operators like AT&T and Verizon are seeing huge growth in their average revenue per user (ARPU) numbers after phasing out unlimited data plans—which means money out of your pocket. In the view of the New America authors, this revenue growth is precisely the point of data caps.'