"Hijacking"? No, those clouds providers are happily hosting phishers. They simply believe doing the bare minimum of half-hearted anti-abuse is more profitable than doing proper KYC and risking missing out on a legitimate customer or two.
Craigslist's revenue, and his wealth, heavily came from pimps and human traffickers. If anyone thinks they weren't aware of what was going on, they're fooling themselves.
When CL shut those sections down, it only did so because state AGs were starting to make a lot of noise about prosecuting them. Now Craig Newmark makes a lot of noise about all the good things he's doing, and it's primarily for SEO because the only other thing he and the other guy were getting in the news for was running a site that was profiting off human trafficking and prostitution.
All those ads went to Backpages, which most people had never heard of until state DAs start going after them. And how strange that Backpages never did anything on its own about the huge influx of sexual solicitation content...