My husband and I were separated for awhile and I was with another man. I am now back with my husband and have a ten month old baby with that other man. He knew I was pregnant and did not care, he actually told people I was stalking him. My husband talk to him about a year ago and was informed that this other man did not want anything to do with the baby. When she was born my husband signed the birth certificate and has been her father since birth. Lately, this other man has been contacting me on some of the social networking sites I visit and I fear he may be trying to get some information to take to family court(he asks me odd questions and tries to get to write that he is the father). Does he have any rights? Was I wrong to put my husband on her birth certificate? Please help me, I only want to do what's best for my child. (I live in NY)

He could have rights if he goes to court to get a DNA sample from your child.
It wasn't wrong to put your husband on the BC.
How much do you converse on networking sites, and what sorts of odd questions?

NYS law states that if a child is born to a married couple the husband is presumed to be the legal father. So there was nothing illegal about your husband signing the birth certificate. He is, by law, if not biology, the child's father.

NYS also keeps the best interest of the child in mind here. It limits the rights of a 3rd party to challenge paternity, especially where the legal father has acted as the child's father.

So the bio father, at this point has no rights. He MIGHT be able to file a challenge to gain rights in court. I would consult with a local attorney to see what the possibility of that is.