This is a common problem and DMCA.com has several services to help with stolen facebook photos.
1. DMCA Professional Takedown Services - if you have found your stolen facebook photos on another website our professional takedown services can get them removed.
2. DMCA's Do It Yourself Takedown Part of the Protection Pro service, this takedown toolkit comes with everything you need to submit DMCA Takedowns on your stolen photos.
3. DMCA's Facebook Watermarking Tool - Use this free service to watermark all your facebook photos. Put would be thieves on notice.
Join DMCA.com on facebook: https://www.facebook.com/DMCAtakedown. Check out watermarking examples and follow up with other DMCA.com users and their examples keeping their photos protected.