The Federal Communications Commission is set to fine AT&T $100 million for misleading customers about unlimited data plans.

According to the FCC, “AT&T severely slowed down the data speeds for customers with unlimited data plans and that the company failed to adequately notify its customers that they could receive speeds slower than the normal network speeds AT&T advertised.”

In other words, AT&T is accused of throttling customers who supposedly had “unlimited” data plans once they hit a certain amount of usage – and not being transparent about this practice.

“Consumers deserve to get what they pay for,” said FCC Chairman Tom Wheeler. “Broadband providers must be upfront and transparent about the services they provide. The FCC will not stand idly by while consumers are deceived by misleading marketing materials and insufficient disclosure.”

According to the FCC’s investigation, millions of AT&T customers suffered slowdowns for an average of 12 days per billing cycle.

“The notice provided to unlimited data plan customers about the Maximum Bit Rate policy was not sufficient to enable AT&T customers to make informed decisions about their data plans,” the enforcement bureau found.

“Unlimited means unlimited,” said FCC Enforcement Bureau Chief Travis LeBlanc. “As today’s
action demonstrates, the Commission is committed to holding accountable those broadband
providers who fail to be fully transparent about data limits.”

The fine isn’t final, and AT&T could settle the charges. As expected, AT&T has said it will “vigorously dispute the FCC’s assertions.”

AT&T faces a lawsuit from the Federal Trade Commission over the same accusations.

Image via Mike Mozart, Flickr Creative Commons