The , founded in 1995, has become famous for its personals ads and those for erotic services.
It has now said that it is implementing "sweeping new measures" to prevent its communities and ads from being misused for the "facilitation of human trafficking, child exploitation and other illegal activities".
Ads in the erotic services section will now be charged a small fee, which must be paid by credit card and the poster must supply a working telephone number. Craigslist said that because the posters of such ads will be able to be identified, it should effectively stamp out illicit ads.
However, advertisers in the Los Angeles casual encounters section today included a woman advertising for men who are "down to earth, open minded, clean and disease free... someone who is mobile and generous", adding "no out calls for me" -- indicating the difficulties that it will face in attempting to stamp out the practice completely.
The measures outlined by Craigslist to clean up its site go beyond prostitution to wider illegal activities. The company will be working in partnership with the National Centre for Missing and Exploited Children (NCMCE) and state law enforcers from more than 40 states and territories.
Jim Buckmaster, CEO of Craigslist, said: "Preventing site misuse and improving public safety are our highest priorities and we are extremely appreciative of the encouragement we've received from the attorneys general and NCMEC."
Craigslist has been attracting the wrong kind of publicity for ads such as that placed by a Vancouver couple offering their seven-day-old baby for sale for $10,000, and one placed by a woman in Michigan who was seeking someone to kill a love rival for $5,000.
Buckmaster said: "The incidence of crime on Craigslist is actually exceedingly low, considering the tens of millions of legitimate ads posted each month by well-intentioned users. But no amount of criminal activity is acceptable, and as Craigslist has grown, we have become aware of instances where our free services were being misused to facilitate illegal activities"
Craigslist plans to stamp out ads that do not conform to its terms of use by filing lawsuits against businesses that sell software and services designed to evade the conditions.
It is also refining the protocols for blocking inappropriate postings and ads for illegal services. Users will also be able to flag inappropriate content for fast removal, and a system for tagging adult content will be implemented so that parents can block those areas of the site from minors.
Any revenue raised from ads in the erotic services section will be donated to charity, Craigslist said.
Craigslist is currently embroiled in a dispute with eBay, which owns a 25% stake in the company. The two companies are arguing over whether or not Craigslist is trying to force eBay to reduce its stake in the company, and a rival free ads service launched by eBay called Kijiji.