When I was an undergrad we had a robot that looked like a 44 gallon drum on wheels that could be controlled by anyone over the internet. There was an open internal staircase in the middle of the floor going down, top floor, and I swear the robot spent most of the day hanging around the top of the stairs with some malcontent on the other side of the planet trying to drive it down the stairs. They never succeeded, there were too many sensors in the floor around the top of the stairs and if the sensors every went down the robot would stop dead.