My uni has phone charging stations with micro USB + lightning adapters and a monitor displaying ads for stuff around campus + other sponsors. What kind of trouble might you be able brew with a Raspberry Pi hooked up to one of those and some sort of root privileges?
They don't get a lot of use by students who are right to not really trust the stations and consider them a waste of money, so collecting phone info with them doesn't sound like it'll yield much at all. The monitors themselves seem more promising since they could display whatever given the chance.