I gave confidential information to my employer about a peer in management who was using drugs and possibly dealing them where we worked. I was told I would stay anonymous. Several months later the peer contacted me accusing me of being a snitch and getting him fired. When I asked how he found out he admitted that upper management told him I was the one that gave the information. Now he is all over facebook telling everybody that I am a snitch and telling them what happened. Is there anything I can do?