My brother was a student at Rice and told me a story that you may want to look into. My details could be way off. There is a statue on campus that mysteriously changed directions over night. Somehow on the middle of a quad students had rigged up a way to lift the statue off its moorings and turn it facing the opposite direction. It wasn't even noticed immediately. School officials couldn't figure out how it was done, and more importantly the grounds crew was incapable of turning it around. The work had to be bid out to local engineering firms, most of which could not figure out how to do it at all. Eventually somebody was hired to do it and they managed to damage the moorings in the process. So an unknown group of students, without the benefit of heavy construction equipment (which surely would have been spotted by campus security) accomplished successfully what the pros could not. Not something anywhere near your top ten list, but noteworthy