It would be easy to say go after them, but you have a lot of proving to do, including that the nudes w/o faces are really you, and how are you going to prove they were taken when you were 17. And how did they get them, did they take them or did you take them and send them? They should not have ended up on the net and the site did the right thing by taking them down, but I am not sure you are going to have an easy road if you try and go after the person who you think probably did it.

I would be thankful the site took them down without a big kerfuffle.

I can feel the downvotes coming already. Before you hit the button, know I did not make this system we live in and there are a lot of times I do not agree with it. But it is what it is and it works the way ir works and to go into something like that is going to be easy is sadly misleading.

So instead of misleading you, I would say talk to a trusted lawyer before the cops. They can give you a much more realistic opinion of what you have to deal with and the odds of that happening, and also sadly, the cops often do not know the law. Lawyers do. My mothers BF went off and slugged my sister one time, cops were like who cares? She called me, I called my lawyer. He called the cops. All of the sudden they cared very much.

I wish you the best in whatever direction you go in.