From what I've seen yet, it's only possible to sell personal data via contracts (couldn't even buy anything with other people's *mazon accounts). However, there seem to be some tools to use someone else's credit cards further into the game - still no meaningful "exploiting", if you are awaiting some sidequests (or at least peeking into anything private).

Ok, thanks for the info. I think I'll pass for now then, as I enjoy a bit more freeform hacking style.