A lot of people will learn this the hard way with BTC, especially as more and more ordinary Joes start using it.
That's why this thread is here. If you want to put a chunk of your money somewhere new, you'd better do your research and discover all possible points of failure. Then protect against them using a COLD WALLET and TRUST NO ONE.
Use Escrow if needed, use it from a TRUSTED MEMBER that has a good WoT rating (this is arguable, I know, but every little bit helps), and make sure there are no questions from any of the 3 parties before starting a transaction.
Good luck people. Stay safe and read up on everything.