Last weeks vote of approval by MetroPCS (NASDAQ:TMUS) shareholders for the sale of their company to T-Mobile USA will give the fourth- and fifth-largest U.S. mobile carriers a combined 40 million-plus subscriber base and a potentially large 4G LTE footprint in major markets.

But T-Mobile's recent ad campaign characterizing itself as the "Un-carrier" by not holding its subscribers to long-term contracts has gotten the company into some hot water.

The Washington State attorney general called the ad campaign "deceptive" by not specifically informing customers that if they decide to leave the carrier, they will still be liable for the full price of they phones they would be buying. Fool contributor Dan Radovsky explains it all in the video.