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AT&T Reports 81 Percent Rise In Q2 Profit
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Even if you watch the data usage on your cell phone like a hawk, chances are you don't pay much attention to it at home because you pay a flat monthly rate with no penalties for high use. But that might change soon.

On May 23, AT&T began implementing data restrictions for certain customers on their home Internet service. Depending on the plan, U-Verse customers will face caps of 300 GB, 600 GB, or 1 TB. The previously unlimited service now costs an additional $30 a month.

According to Wired, some users previously had a cap—of 250 GB—but it wasn't really enforced by AT&T, so customers didn't have to pay attention to usage.

This move proved ingenious, because having set the precedent—albeit unenforced—AT&T could announce this news as an increase in data allowance, instead of the restrictions they really are.

Adding restrictions seems like a step back, similar to carriers' curbing of unlimited phone data plans when they were phased out a few years ago. But that was easier to justify as smartphone adoption skyrocketed and files became huge. Cable Internet seems different though. It's not wireless from a scattering of mostly unseen towers—it runs through fat cables you can see on telephone poles, and plugs in through a modem.

If you're affected, you'll have to figure out how much data your allowance you should sign up for. AT&T offers some tools and recommendations—1 TB equals 400 hours of HD video—and you can buy an extra 50 GB for $10 if you go over. For context, AT&T says that currently 4% of customers are over their future allowances.

As for other companies, Comcast has caps similar to AT&T's. Time Warner has said it wants to have unlimited Internet, always. Verizon has said in the past that FIOS doesn't cap Internet, even though some people beg to differ, complaining of warnings for excessive data use. But given how quickly Verizon and AT&T match each other's moves, it's possible FIOS customers will start counting gigs as well.