The number of Erotic Services listings on Craigslist have gone down so significantly over the last 12 months that the company describes the results as “spectacular.” The news comes less than a week after the Cook County Sheriff’s Department filed a lawsuit against the company for facilitating prostitution, but Craigslist insists that it’s doing more than enough to fight illegal activity.

Craigslist has seen a “spectacular” drop in Erotic Services listings since it began implementing various verification methods in 2008, the company said this week. In five major cities across the US—Chicago, New York, Atlanta, Seattle, and Los Angeles—the drop has ranged between 90 and 95 percent over the last 12 months, and the remaining ads are “much improved” in their compliance with both Craigslist Terms of Use and local laws.

According to a post made on the official Craigslist blog, the company continues to work closely with law enforcement across the country to arrest those engaged in “the horrific crimes of human trafficking and exploitation of minors.” Additionally, the revenue generated from Erotic Services listings is earmarked for donation to charity, which Craigslist says will begin “soon.”

The news comes less than a week after the Cook County Sheriff’s Department in Chicago sued Craigslist for facilitating prostitution. Sheriff Thomas Dart said in a news conference that his department had been making arrest after arrest due to Craigslist, leading to his lawsuit seeking the closure of the Erotic Services section of the site, as well as a reimbursement of $100,000 for the costs involved in pursuing Craigslist-related prostitution cases over the past year.

Craigslist CEO Jim Buckmaster [pictured] said he was “mystified” by the lawsuit. He said that Craigslist had met in 2007 with the Cook County Sheriff’s Department to discuss the purposes of the Erotic Services section, and that “inexplicably, Sheriff Dart apparently bypassed the Illinois Attorney General’s office, and filed this complaint through a private law firm.” Buckmaster said that he planned to vigorously defend Craigslist against the lawsuit.

This suit was filed despite Craigslist’s efforts to clean up its act, including a November 2008 agreement with the National Center for Missing and Exploited Children (NCMEC) and the Attorneys General of 40 states to implement a number of protective measures. In addition to a new phone verification system launched in March 2008, Craigslist began requiring credit card verification for each listing in the Erotic Services section. These two measures were meant to make posters more accountable for their listings, as Craigslist could blacklist phone numbers or credit cards that had posted “inappropriate” ads in the past. As a result, the company has apparently seen a dramatic drop in Erotic Services listings, which, of course, was the goal.

Clearly, a drop of 90 to 95 percent in major US cities is a positive development, but it’s not enough for those who want Erotic Services closed altogether. Those people seem to believe that if that section of the site is gone, prostitution listings on Craigslist will cease to exist—a faulty assumption, as the reason it exists in the first place is to pull those listings out of other, less-regulated parts of the site.

Craigslist is trying to make it clear to the public that it’s working hard to reduce illegal activity as much as possible, though Buckmaster noted that the company can’t be held liable for content posted by its users. This much is true: section 230 of the Communications Decency Act has protected Craigslist in the past when it came to discriminatory housing ads, and would likely protect it again over prostitution listings.