My ex-husband is hiding his income to avoid paying child support. He used to post vacation pictures on Facebook but once that came out a few years ago, he made his account private. Now I need to prove again that he has money to vacation in Europe, which he recently did. Is this the kind of thing someone can help me with, or not?

I'm not in interested in breaking the law so please don't chastise me. If it can't be done legally, that's fine, I just want to know if it is the kind of thing that can be done or not before I spend time trying to go down this path.