The Feds are suing Sprint for overcharging them.

The government says Sprint Communications padded its bill to the tune of 21 million dollars, for assisting the government to carry out wiretaps.

The law allows companies to claim "reasonable expenses" when they're required to assist in wiretapping, but the feds say Sprint "knowingly submitted false claims" to the FBI, the DEA and other agencies over the last few years, inflating the cost more than 50 percent.

The FCC ruled years ago that companies couldn't bill the government for upgrades to wiretap equipment, but government lawyers say Sprint hid those charges in its bills.

--Rob Archer