yeah, sometimes. it can actually be pretty fun, and i don't think it usually really seriously harms anyone. i don't like, join websites entirely to troll them or anything, but i do it sometimes.
when i was younger i loved it. i remember when i used a dupe account to spam a forum with enough gifs to make pages crash, and i never told anyone it was me and i kept using that site for months afterwards and nobody ever found out

14 year old me was a mess.