I was one of the lucky NetBank customers that suddenly found himself without a bank account this weekend. Thankfully, I'm not rich (yet) so the FDIC will ensure that I don't lose any money.<p>Potentially very painful lesson learned: Yes, banks can go out of business. FDIC only covers you up to $100,000 if this happens. When you get rich with your startup, keep your money stuffed in your mattress.