[ssmith]

...not illegal and certainly immoral. The issue becomes the the closeness of the person to have access to secrets and the possibility of blackmail and or divulging secrets through 'pillow talk'. That is how I see it anyway.

I would guess that Petreus will still have to be closely monitored since many enemies would like to get access to the infomation he has. Couldn't you just see people offering him favors for information. Of course that is true of anyone with information but once a person has been found to have a weakness in that area it is easier to try access again in that way.
Also the lady was found to have classified documents in her possession.

However, I do think it is great that he has stood up to take responsiblity even if he was about to be exposed for it anyway.