In this case, "wreaking havoc" means that they are randomly running around Harvard Square and refusing to be orderly. You definitely don't see this everyday.
Sometimes bad things happen for a reason. On Wednesday, this was definitely the case. Twitter user @cheenadiabla shared a photo of a tray of mashed potatoes she had dropped on the floor. The dish had been intended for a potluck, but she quickly said "f*ck it." While she was probably expecting sympathy from her followers, they instead delivered a whole lot of scathing reviews of her admittedly terrible looking mashed potatoes. While she took it in stride, admitting it was her first time preparing the dish, some of the roastsare downright mean - and downright hilarious.
How rare is it that we see a text sent to the wrong person evolve into a heartwarming scenario like this one---and with a Thanksgiving dinner invitation to boot! Jamal Hinton is one lucky dude, and you better believe as soon as he shared the original conversation to Twitter, plenty of other hungry teens were ready to beg for their invitations. Fortunately, the numbers have been disconnected!