You friend or the person who shared your friends account was hacking. If you thuroughly read the EULA or whatever Valve scandelous agreement is, it says you can share steam accounts. Your friend should call and ask for the logs and records and see if his friend was hacking. Believe me, Valve wouldn't ban for sharing accounts. I share my cs:s account and others 24/7; Paradox knows. Plus, it doesn't make a difference, because if they DID log the IP as "this IP only", then those who switched internet service would be banned from steam. I'm not accusing you and I am NOT trying to start ANYTHING, PLEASEEEEE don't think that! I'm just telling you to tell your friend to look into why his account was banned, because losing fifty dollars is questionable and deserves a good case!! Hope you get it back!!!!