On one hand posting a photo of someone in particular without their permission is a form of doxxing ie personal information-their appearance and probably some arrest info.
On the other drunk driving, alcoholism, drug addiction should be associated with negativity. Describing them or talking about your AH new gf in detail without personal information is okay. But just for one's own security I wouldn't make it personal to the point of releasing personal information. It could start a war of revenge posts. Anonymity is what makes this and other forums work ie speak freely.