Craigslist is working with attorneys general of more than 40 US states and the National Center for Missing and Exploited Children (NCMEC), to prevent online communities and classified ads from being misused for the facilitation of human trafficking, child exploitation, and other illegal activities.

Craigslist recently implemented a telephone verification system for the “erotic services” section of the site, requiring a working phone number for advertisers, and enabling blacklisting of phone numbers for those who post inappropriate ads. Phone verification resulted in an 80% reduction in ad volume, and significantly increased compliance with site guidelines.

Craigslist will soon require credit card verification and a small fee per ad for posting in “erotic services,” to further encourage compliance with site guidelines. Paid ads that violate site guidelines will be removed without refund. The company intends to donate 100% of net revenue generated from these ads to charity, with net revenue to be verified by an external auditor.

The end goal should be to avoid this, this, this, and this.