Evil thoughts? Only evil thought I've had is sneeking into that good for nothing bums house that got me questioned by police because he didn't think to have the girls use the phone... for him I have thought much over, let me break it down.
1) I could slip through his bed room window late at night whens he's asleep and slip him some knock out drugs or just bash him over the head real good, then I could cut his tongue out and hang it from the cieling so when he woke up he would be looking at hos tongue with a note attached 'maybe you should renember to tell people'
2) I could wait outside his workplace with a baseball bat beating him and dragging him to my car where I would take him to a room and tie him to a chair and lock his head to where he was staring at his right arm. Then I would remove his eyelids and begin slicing along a vien in his arm while he had no other choice but to watch while saying 'so how does it feel looking for something to help when you know your helpless'

I could make home made Napalm and pour it over his face telling him what fun we're having as good 'friends' as I laughed
4) I could get in a fight with him and drag him to the ground and grind his face into the assphault watching his face get shredded across the blacktop letting him know looks are only going to get him so far when he's pissed off the wrong guy.
5) I could pin him back to the ground while pressing my thumbs into his eyesockets till I could feel his eyeballs crush under the pressure of my thumbs and keep pressing untill I couldn't go any further after that I could tie him to the hood of my car and drive down the highway swirving between traffic.
of course this could all wear off in a week and I may be calm enough not to harm him... but I doubt it.