If all that was at risk was a night in police jail and a slap on the wrist, it would be done, but reading the sentences one faces for election tampering is really chilling.

I would not risk it for a million, I will certainly not risk it for the lulz. Plus, in most cases, it involves (laughably weak) physical security. I am less confident on how to hide my tracks there and I suppose many would-be hackers feel the same.