I dropped my laptop at Apple Store, the Falls in Miami to fix minor cooling system issue on Feb 2. And picked it up on February 4. Cooling system was fine, but when I launched my Bitcoin wallet, I realized that over 10BTC (worth $8500 at that moment) has been transferred from my wallet (https://blockchain.info/tree/111322425) on Feb 3, 20:25, when my laptop was in Apple. It was very stupid, but yes, my wallet was not encrypted.
I checked Mac system logs and it says that my laptop has been booted on Feb 3, 20:36, only 11 minutes after my BTC have been stolen. Looks like someone has connected my laptop as external drive and scanned it before booting it up.
I never used my wallet on other devices. I never download suspicious stuff from the Internet. I never hand my laptop to anyone else. I have not been using my wallet for about a month before I dropped it at Apple.
Nevertheless, I downloaded latest antivirus software and performed full system scan — no viruses.
I filed a police report and talked to the manager at Apple Store. It's been a week and there is no update.
$8500. Nobody cares. I wonder what else people copy from laptops when you drop it for service.
The moral of the story — encrypt your drives.