Computer hackers don't necessarily do jail time.

Someone hacking a single-player video game, to give them increased stats or something, won't do jail time. Even when it's a multiplayer game, someone finding a hack that benefits them is unlikely to face jail time.

Hacking is a crime if you're gaining unauthorized access to a system, especially a remote one. I think hacks involving money and personal user data have different criminal classifications as well.

And that's ignoring the massive number of hackers ("researchers") who actually get paid to do it (many of whom started out doing illegal things).