I think that people need their very own personal things, no matter if they are married or in a relationship or whatever.
If you need someone to talk to, and Yahoo Answers is what you use to vent, she has no right to take that from you.
What other issues are going on here? Why would she take something like your account on Yahoo and want to take it from you? Does she want to hurt you? Is she hurting?
I highly recommend counselling, together. It can teach you both how to communicate - as well as teaching other skills, like respecting boundaries (which it sounds like your wife needs).
She sounds like she feels threatened, and is fighting back in the only way she deems effective.
Edit: I just looked at some of your questions, and it looks like you have issues that need to be worked out as well.
Perhaps she wants you to ask those questions to HER, like she is a HUMAN BEING, instead of strangers on the net.
I more than recommend marriage counselling, I think if your marriage is going to last at all you need to put some more effort into it, into the positive things. Both of you.