Super dumb idea. Seems like a good way to break the USB, or the USB port on your laptop. Laptops are heavy and awkward to hold with one hand. And then to try to fidget with transferring files? Good chance to of dropping the laptop.
Why is he going around defacing public property?
That one scene in the subway station where he puts the USB into some gray clay material...yeah, people won't think it's some kind of explosive device, especially when after stuffing that thing under a pay phone, you go and hook up your laptop and stand there in an awkward position.