I just posted your naked picture on
http://www.cheatinghusband.com and
http://www.pervertedcoworker.com.

I hope you don't mind that I did that without your permission.

Of course, you and I aren't the first people to post compromising pictures of other people without their permission, but regardless of what the "norm" is for other guys what does your own personal sense of ethics and common sense suggest the proper course of action should be.
Some chicas kindly (or naively) agree to let guys take their picture on the foolish belief that it is just for that guys later personal enjoyment (a momento of their private session). Say what you will about the wisdom of such thinking, you can imagine their later anger and chagrin when that naked pic winds up on a public (or semi-public) monger site where, theoretically at least, their novios/esposo/familias could find them. Of course, there are certainly some chicas who have no problem at all taking that risk, but then if that is the case there is no harm in asking their permission to do so first.
If they say yes, then fine post as much as they allow. If they say no, respect their wishes and save the photos just for your personal enjoyment (or perhaps to show your friends over drinks). If you don't ask there may not be any problem if they really don't care (or if they never find out). However, if you don't ask and they really don't want the pics getting out (as many don't) and you then post and they find out (as they often will due to the chica-grapevine), then it can have huge negative repercussions on every other guy who comes after you and really does just want to take a few pics for his private collection (plus on yourself if you ever want to session with that chica again).
Already, many if not most chicas are extremely wary about guys taking their pics because they (or else many of their friends) have been burned by the less responsible guys amongst us. More broadly, it fosters the impression of us as a group as being guys who can't really be trusted in general whether it is for taking pictures, paying as promised at the end of the session or whatever. We already have that impression of most chicas. Shouldn't we at least try to stay on the high moral ground in our dealings with them?
RE: Palynx's latest comments, posting postive or negative review commentary is one thing. Even posting pics of another person in a public setting (ie probably fully clothed) is another. However, posting easily identifiable pics of a someone in a compromised position that was taken in a private setting is something else altogether. In the US, it is legal to post descriptions of what happened in a private meeting. It is legal to post pictures of others taken in public (as in the celebrity paparazzi scum who technicaly don't break any laws). It is also legal to post mug shots of guys arrested in prostitution stings (although most would not like it very much). But, generally it is not legal to post private photos taken in a private setting (or setting where a reasonable expectation of privacy could be assumed). Nor is it even legal to post a private audio recording where one side was unaware they were being taped.
Does her consent to being photographed really amount to a consent to your doing whatever you want with the photo? If you think so then I guess you can explain why professional photographers, who could naturally be assumed to post their photos out in public, are required to get signed "model release forms"? But regardless of the legality, there is the basic concept of ethics and the golden rule "Do unto others as you would have them do unto you." If you would have no problem with chicas posting naked pics of you or can't even understand why other mongers might have a problem with that, then by all means post your unauthorized naked pics of chicas. Just don't wonder why on your next trip, all the chicas have become so wary of letting you continue to take their pics.