BOSTON, Mass. (Legal Newsline) - The CEO of Craigslist says Massachusetts Attorney General Martha Coakley's vow to tame the online classified site's sex ads could spell doom for the popular trading post.

An amendment of federal law "would likely accomplish nothing other than forcing online service providers to stop moderating user-generated content and start falling back on... the First Amendment protections often cited by print media," CEO Jim Buckmaster told the Boston Herald over the weekend.

Buckmaster warned the end result could be "ceasing to carry user-generated content altogether."

Coakley fired back that the site is a proven public safety threat because it chooses not to stop a massive daily influx of ads from Bay State prostitutes.

"The fact is that if Craigslist has the ability to screen the ads, it is not being done well enough," Coakley spokesman Corey Welford told the Herald over the weekend.

"That's why the attorney general believes we must continue to look at this and find better ways to protect people."

Coakley contends the Communications Decency Act must be changed so it no longer gives cyber-middlemen such as Craigslist immunity from prosecution for the content of its ads.

But Buckmaster said that immunity allows Craigslist to pick and choose which ads to edit or remove, without being liable for all ads on the site.

"To our knowledge, Craigslist is more intensively moderating ads posted to its adult-services category than are any of the countless other advertising venues, online or offline, that carry such ads," he told the Boston newspaper.

Many, including Coakley and other attorneys general, disagree and say the site is doing little to prevent or control the ads.

Earlier this month, a U.S. District Court judge turned down Craigslist's request for a permanent injunction that would've banned South Carolina Attorney General Henry McMaster from attempting to prosecute the site.

Last year, McMaster threatened to prosecute Craigslist executives for abetting prostitution unless the company blocked adult ads.

McMaster gave Craigslist a 10-day window on May 5, 2009 to remove what he said were South Carolina sections on which prostitutes were soliciting themselves and graphic material was being posted. On May 13, 2009, Craigslist reached a nationwide agreement to drop its erotic services section.

Craigslist responded by going to court to request an injunction banning the attorney general from threatening any further criminal investigation.

U.S. District Court Judge C. Weston Houck turned down Craigslist's request for a permanent injunction, saying any threat of prosecution is too remote to warrant action.

From Legal Newsline: Reach Jessica Karmasek by e-mail at jessica@legalnewsline.com.