I’ve often thought about this question. Here’s a nice answer. It was nice to see that Schwab does offer a guarantee, but who knows if they’d really cover my loss due to my account being hacked.
http://www.kiplinger.com/personalfinance/columns
I think that their non-technical business processes are key to protecting you against someone taking your money. By sending notification to your registered address for any address changes and not allowing withdrawals for 10 days after an address change, it sure seems like they are minimizing the risk. I wonder if they would allow electronic transfers.
A lot of online brokers are offering account protection now. ETrade, Schwab and TD Ameritrade for sure and I am sure others do or soon will in order to stay competitive.
I would think your risk of having your account information stolen is relatively minor so long as you use common sense.