It is going to sound strange and impossible, but it just happened to me about an hour ago. After logging in to my account (typing my password) OSX started asking about iCloud settings. Then, it loaded a fresh default desktop, default dock, default mouse settings, as if my OS account was just created. All the files in the home directory are gone, all the applications behaved as if I just installed them. OS just went back to factory settings. All my documents, source code, videos, family photos (40.000 pictures, 10 years of shooting), were wiped out. Interestingly, my applications were still there (Firefox, Eclipse, Photoshop etc). But everything stored in the home folder (including ~/Library/Application Support/ and so on) were deleted. The bootcamp partition is intact. Yes, I have a Time Machine backup from just a week ago. I am in the process of restoring the system. So to sum things up, all I lost was 9 hours of restoring the OS. Why am I writing this? To warn you. WHAT THE ****, APPLE? HOW AM I SUPPOSED TO TRUST AN OS THAT CLEARS ITSELF RANDOMLY? It was my first mac and this is my last one. I'm going back to my Debian. Guys, make backups. If anyone has any idea how this could happen, please share your thoughts.