COLUMBIA, S.C. (Legal Newsline) - First, South Carolina Attorney General Henry McMaster threatened craigslist with a criminal investigation. Then, the classified advertisement Web site hit with McMaster with a lawsuit.

McMaster had given craigslist a 10-day window on May 5 to remove what he said were South Carolina sections on which prostitutes were soliciting themselves and graphic material was being posted. On May 13, craigslist reached a nationwide agreement to drop its erotic services section.

Craigslist is now seeking an injunction that would prevent McMaster from threatening any further criminal investigation.

"Despite craigslist's legal immunity from criminal or civil liability under state law for unlawful third-party content on its website, and despite the numerous good-faith actions that craigslist has voluntarily taken to deter abuse of its service by third parties notwithstanding its legal immunity, Defendant McMaster has persisted in threats to criminally prosecute craigslist on the basis of third-party content appearing on the craigslist website," says the suit, filed in South Carolina federal court Wednesday.

After the deadline McMaster imposed passed, he issued a statement on his Web site stating that the craigslist South Carolina site continued to display prostitution advertisements and pornographic material, and that he had no alternative but to move forward with his criminal investigation.

"Given Defendant McMaster's persistent and continuing public threats, craigslist is presently faced with the untenable choice of either completely shutting down all portions of its website that are directed at South Carolina or else putting itself and its management at risk of imminent criminal prosecution," the suit says.

In place of the old erotic services section is a new "adult services" category for which new listings would be reviewed individually. Posts to the new section will cost $10, which is twice as much as the fee was for erotic services listings.

Nude or graphic photos will also be banned from the adult services section.

In November 2008, 43 stare attorneys general brokered a deal with Craigslist that the site would crackdown on inappropriate content and illegal activity in its erotic services section.

In April, Illinois Attorney general Lisa Madigan sent a letter to craigslist CEO Jim Buckmaster, calling on the Web site to shut down the erotic services section amid evidence Craigslist had breached its agreement by not developing an effective screening procedure for ads.

From Legal Newsline: Reach John O'Brien by e-mail at john@legalnewsline.com.