I don't see a problem: revenge doesn't imply a justification.
I do see a problem with the proposal of "lynching" since it suggests the aggrieved party using Photoshop software to portray their victim getting lynched, which is more traumatic for everyone than "pictures of people with not enough clothes on which were meant to be private", which seems to be what we're actually discussing, as well as the other thing I just said perhaps.
I also see a problem distinguishing the particular offending pictures of people with not enough clothes on from very widely freely available pictures of other people with not enough clothes on, including people who may, coincidentally or otherwise, look very like the people who don't want their own pictures with not enough clothes on to be circulated, but are different, consenting people.
Well, I suppose that if I, an overweight fifty year old man, agree with you to pose for pictures on your Facebook in the guise of your ex-girlfriend with not enough clothes on, then it is liable to be humiliating to your ex-girlfriend, but I'm not sure exactly how illegal it should be. This is hypothetical: I'm not going to do it. No. Stop asking.
Just cheer yourself up with some pictures of Sophia Loren in "The Millionairess", the film which inspired the rather pointed comedy show title "Peter Sellers Is Dead" (they changed it but kept the theme tune).