A 2017 U.S. Senate subcommittee report charging employees at backpage.com with editing the website's online ads for prostitution has revived debate over the willingness and ability of such websites to screen ads for unlawful commercial sex activity. This study sheds light on the controversy by revisiting the dispute surrounding similar advertising on craigslist.com. Using an observational pre-post research design, I examined unique data collected from commercial sex ads on a North Carolina Craigslist site to assess the impact of enhanced ad screening measures that Craigslist implemented to address misuse of its ad hosting services. Results indicate that Craigslist's switch to a manual review of ads led to significant decreases in illicit ad content, temporarily inhibiting online marketing of commercial sex by regional advertisers.