Someone posting nudes of me on Twitter. What can I do?

[dude]

I need help. There is this account on Twitter who keeps tweeting nude photos of myself & sending it my friends online. I have NO idea who this person is but he seems to have a great dislike of me, since he's mainly focusing on me. I don't know how he acquired the naked photos but I'm at a point now where I've had enough harassment from him. This kind of thing can ruin my life. I need to know what I can do to stop him. I'm not talking about just blocking him & going on with my life, I mean I really want him to STOP. I've emailed Twitter but they just suggest to block.

I'm more than willing to get the law involved.

P.S. They were taken two years ago. I know in a way it's my fault but to have someone send it to my friends is ****** up.