Apparently he got busted/exposed, then resigned..... If I was Barack, I would have sacked him, fancy the CIA chief getting caught! I would have thought if anyone should be able to get away with that, the chief of the CIA should!
AFAIK, the CIA does not have a domestic collection role, though they may be involved in analysis that overlaps domestic activities. To put it another way, it would (I believe) be illegal for the CIA to spy on a US citizen within the USA and/or to interfere with an FBI investigation. The FBI and, also now, Homeland Security have the US domestic spying role ... AFAIK.
AFAIK, the CIA does not have a domestic collection role,
I think you are 100% correct,
but since when has the law ( in any country ) got in their way.
Maybe they should all move to France and it wouldn't be a problem.