For those unfamiliar with the trolley problem, the most interesting thing about it is how people react differently to different variations of the problem. The brutality of pushing a man onto the track vs pulling a lever changes a lot of people's opinions.
Even better is the "Theseus Trolley" (Trolley Problem + Theseus' Ship): if you pull a lever to switch the train to one of the tracks and during its course every single part of the trolley is replaced, is it the trolley that hits the people the same trolley that you commanded and thus can you still be hold responsible for the deaths?