Did I get hacked?

[fryjack2]

I have yahoo as my home page. I've been signed in for a few hours in a different window. I just went to it and read a story off yahoo. I noticed up in the corner, it said "hi S." next to sign out option. It has me signed in as panzicas99. I have no idea who that is.

I went to the mail tab and it has me down as my regular user name but is asking me to sign in again. Whats going on?