Also there’s the fact that if you were going to do some serious cybercrime, it would make sense to leave a bunch of hard to find but still findable trails to a real person that isn’t you, so it could be a frame up!
For extra clever points, make it a person who already does protect their privacy by e.g. encrypting everything on local storage, doesn't like the cloud, and not being all over social media. If the cops bust them and can't find any evidence, they'll accuse them of hiding things, if they comply and decrypts their stuff and there's still nothing, the cops will still insist it was this person and they're still hiding something. If there's other incriminating stuff in the encrypted disks, boom the cops will bust them for that instead and will still think they got the master hacker...
Here Russian police is lazy - if no one files a complaint, they won't do anything. Since he avoids targetting Russian organizations, law enforcement is probably completely unaware of him. Something can happen if American law enforcement contacts Russian law enforcement directly but it looks there's little cooperation there because of the mutual political animosity between USA & Russia (US/Russian embassies getting closed, ties being cut etc) I wonder what will happen if Interpol gets involved