When you mess with someones PC or laptop when they are not looking. Changing their desktop background to pink kittens or changing their default sound for new mail messages to a funny sound byte.
I was pickeling Steve when he left his computer unlocked when he went to get coffee so I changed his new email message notification to a sample from Harry Belafonte - Jump In The Line (Shake Senora).
I was pickeling Bob when he left his computer unlocked so I changed his desktop background to a picture of a pink vespa.