can you report pms?
Yes. But I'm not sure how exactly.
also who can see private messages... without hacking...
I assume only the sender and the receiver in normal cases.
I presume that, since PMs can be reported for abuse, if someone reports a PM it is then subject to some sort of review.
I expect that if the FBI showed up with a valid search warrant for a given person's PMs, they would be granted access.
But these are assumptions, presumptions, and expectations on my part. I don't have concrete knowledge.
Does a2k have any "terms of service" or some such? Perhaps the information is contained there.