AT&T is accused by the FTC of throttling customers with unlimited data plans.
AT&T Responds To FTC Throttling Allegations : Read more
AT&T Responds To FTC Throttling Allegations : Read more
They also do not seem to know what the word unlimited means. I would love for the courts to bring this out and say, "No, you cannot redefine common words to mean something else in your contracts. If you mean something else, say it. Otherwise, we will hold you to it.".