We know Google Adsense checks all the user account websites for spams and etc that go against their policies. I mean with so many accounts with them, do they have a bot to do so? Or they do have so many employees to do such work? Appreciate any replies or viewpoints, thank you!
Lots of bots that have safeguards built in. There are pretty obvious ways that most people try to game the system (fake traffic, stolen content, bad links, etc.). They know what to look for and when to shut it down. They built the system, it is the core of their business model, they'll go out of their way to come up with means to protect it.
first, bots check websites. if they find any issues, they flag. Then, those flagged items are manually checked by google employees.