https://techcrunch.com/2019/01/15/why-google-engineers-worked-full-time-to-combat-sex-trafficking/

When the government seized classified-ads site Backpage, forcing it to shut down in April, it became a lot harder to find and locate potential victims of sex trafficking. While it was symbolically good that the site, whose CEO later pled guilty to charges of sex trafficking, shut down, it created a significant technical challenge for law enforcement and the organizations trying to help prevent sex-trafficking, Google Senior Software Engineer Sam Ainsley told TechCrunch.

“Once Backpage was gone, you were looking at an ecosystem in which all of those previously more centralized advertisements [for those being sex trafficked] are being redistributed on much more websites,” Ainsley said.