https://www.wired.com/story/ftc-att-unlimited-data-throttling-fine/

AT&T has agreed to pay $60 million in a settlement involving secretly throttled unlimited plans in 2011, the Federal Trade Commission announced Tuesday. You might assume the fine has something to do with the broadband industry’s liberal use of the word “unlimited,” given that AT&T slowed connections to a crawl once customers had used a certain amount of data. Unfortunately, you’d be wrong.

Back in 2010, AT&T stopped offering "unlimited" data plans to new customers and offered a choice of 200MB for $15 per month or 2GB for $25 per month. Those who had previously signed up for unlimited data could keep their old plans. But in 2011 the company started throttling the connections of those customers with grandfathered unlimited plans if they exceeded as little as 2GB—and never actually told those people what was happening, according to the FTC.