I was nice enough or dumb enough to let a friend of mine use my MacBook for a few hours. Fast forward a few months later I find out he has been reading my emails and looking at my web traffic. I quickly performed a factory reformat and re stalled mountain lion. After a few weeks I find out that he is still able to hack my system. I then did a 7 times erase and assumed the problem was fixed. Of course it's not and he is still able to view my emails. I changed my passwords over and over and he still gets in. I did some research on Line and found out about a back door recovery partition virus or hack that he could have done. But from what I can read online once my computer has been hacked like this there is no way to fix it. Can anyone confirm this. When I change my passwords on sisters computer I had no problems but after a few weeks I logged into mine and he seemed to get the passwords. Sorry for the long question but thank you in advance .