I'm sure they (META and private companies) are doing that already!
It's a new world.
No, they don't go after it because it's immoral because they're coming here to work illegally. Whether we like it or not, that's the law, and some might even think about overstaying their Visa waiver for years, I know a guy from Uruguay who's been doing that for over 20 years.
Btw we're still far from Chinese level of vigilance but the technology already exists!