April 5 2011 news by arstechnica

AT&T. 150GB data caps will kick in for AT&T DSL customers as of May 2. First time over, you get a disciplinary message. Second time, "AT&T will send you a notice advising you that the next time you exceed your allowance-the third time-you will be billed $10 for each 50 GB of data over your allowance."

Time Warner Cable. TWC abandoned its disastrous experiment with 100GB for $75/month in 2009. But the company still has an "acceptable use policy" that lets it reel in anything it experiences as "abuse" of its network, "including the use of excessive bandwidth." It has no hard caps, however.