So I played a ranked game and played terribly. Normal for me, but that was 2 days ago. When I log on this morning, I notice my banner, settings, enemy outline color, cross hair, etc. Are all changed. I thought it was a friend of mine that wanted to play on my account at first, but after asking and no one knowing anything I looked further into my match history. The person who used my account while I was at work, played 2 games and friended 3 people. The first game they played was with the top fragger in the last game I actually played (I did NOT friend them yet they were on my friends list) and the second game was in a high plat/ diamond lobby and the account stealer topped team with a 77% headshot. By now I've changed all my passwords and plan to try to get some info out of the new additions to my friends list, but I hope that riot doesn't think that I was hacking cause I average 11% hs. Anyways this was a very weird thing so I thought I would share.