The moment you get mitigating circumstances because you just did it for fun is the moment when everybody starts doing it "for fun". Plenty of crimes might have a "thrill" component. This doesn't justify them at all.

The guy accessed other people's email accounts. The punishment for "hacking the elections" is one thing, accessing someone's email account goes way beyond that. So even comparing it to abusing a paper ballot system is not at all appropriate. It's comparable to someone opening up your mailbox, reading your mail, then sending some in your name. For fun.