If you're an AT&T customer, you may have noticed your phone working slower when trying to go online, watch movies or when using an app.  Your so called 'unlimited data plan' may have been 'throttled' and the FTC is suing because of it.

The FTC claims AT&T 'failed to adequately disclose to its customers that, if they reach a certain amount of data use in a billing cycle, AT&T reduces – or 'throttles' – their data speeds to the point your phone becomes difficult or nearly impossible to use.'

The suit says, throttling began in 2011 and has affected 3.5 million customers more than 25 million times.

The FTC says the company 'misled millions of its smartphone customers by charging them for 'unlimited' data plans while reducing their data speeds, in some cases by nearly 90 percent.'

FTC Chairwoman Edith Ramirez says 'the issue here is simple: ‘unlimited’ means unlimited.'

The case is now in the hands of the court.