Minnesota Attorney General Lori Swanson filed suit against Sprint Nextel Thursday, saying she has received hundreds of complaints from residents that the carrier extended their contracts without consent. Some residents, she said, complained of being threatened with a $200 cancellation fee for wanting out of contracts they thought were expired.

"The company has used hidden trip wires to trap unwary consumers into lengthy contracts simply because they made small changes in their plan," Swanson said in the suit.

Swanson claims that Sprint violated state laws that require consumers receive proper information and give knowing consent before contract terms are altered. She also said she is investigating complaints against other carriers. She decided to go after Sprint first because she received more complaints regarding its contract terms.

The suit seeks restitution for victims and asked the court to penalize Sprint up to $25,000 per incident.

Sprint did not respond to a request for comment, but spokesman John Taylor told the Associated Press, "It is Sprint Nextel's policy to go over the contract with the customer so they understand all aspects of it."