Perhaps this is why Pandora has the annoying "I'm still listening" button, so they don't have to pay out royalties on things their users aren't listening to.
Somewhat related: It's also probably why services like Netflix have the same thing built in ("I'm still watching" button after watching like 3 episodes of a show without clicking buttons), so some bot computer doesn't just stream and record everything.
I always figured that button was for people who fell asleep or had to leave their computers. It would be trivial to automate that prompt away for a malicious user.
It is really trivial, there are several programs that automate UIs, I remember them from trying my hand at automating trading for a game which didn't provide an API :) .
Automate 7 was really impressive, and they're at version 9 now
Youtube's playlists also have it. It's annoying when I'm listening to a playlist at work and it suddenly stops, although if I'm deep enough in the zone I don't notice it until some minutes later.