Privacy Violation

I am currently in litigation with my property management. My sister in law also rents from the same company. When she went in to pay her rent the landlord proceeded to tell her about the problems he has with me and my roommate. I am wondering what, if anything, I can do in response to this privacy violation. He revealed personal information about myself and my roommate to another tenant. He told her things that were untrue and now she is afraid that she is going to be evicted because she is related to me. She strongly expressed the fact that she did not want to talk about my situation with him but he insisted and made her feel extremely uncomfortable. What can I do? Please help!

If someone publicly says or writes anything factually untrue and it damages you, you indeed can sue for slander, libel, defamation, interference with business relations etc. -- or at least threaten to do so and give a warning.

Although this was your LL, this is not a LL-Tenant issue. Move this to personal liability or some other thread. It is not LL-tenant law that was violated here.