Just so everyone knows, your local bank branch takes deposited checks, scans them into a computer, then transmits that image to the issuing bank. However, that system is different because it is managed by a bank teller, uses a secure network, and is regulated just like any other bank process.
I still don't trust people to successfully deposit a check on their own using their camera, but then again, it doesn't sound like the bank trusts them either, considering they have to have a line of credit and insurance with the company.
Fraud via this system would be less likely than fraud with the existing system. The transaction is tied directly to your phone and bank account, so how would you plan to get away with it? Bad checks are always caught, but usually they have been cashed, and the perp is long gone.