The lifts are awful. The escalators are just as bad. Apparently the nastiness the escalator maintenance crew deals with is pretty fetid stuff [1]. Well that's what you get with people who find the bottom of an escalator the coziest place to sleep. It's a shame for both the homeless and the system. But yeah, dont touch any surface within the system unless you're prepared to wash thoroughly

[1]http://m.sfgate.com/bayarea/article/Human-waste-shuts-down-B...