Refresher: journalists always lie.
Banksy probably isn't a State-run op. They do stupid shit all the time, but banksy isn't quite lame enough to be full CIA. Ref: Pollock. But what do I know?
However, you've heard about banksy, therefore what you know about him is false.
Myth: dude runs all over England putting up elaborate paintings 6+ feet tall, and is never caught on security camera.
Reality: yeah, no.
I figure he was caught and then someone bought him out. There was a real person as a seed but it's all theatre at this point. Maybe a team of trust fund babies do his art now, that sort of thing. High roller trolls. Maybe got three murals done before everyone in the know knew exactly who he is.