I'm a retired banker, too. I was in the "back room" as a systems support/programmer person. And you're right -- banks do as much as they can to protect their customers' money WRT fraud, theft of funds, etc. There are a lot of safeguards, and they are quite sophisticated, but the account owner has to do his/her part. And yes, one way to risk losing your money is to use a Wifi device which is unsecured/unsafe.
People out there are smart and always on the lookout for free & easy money, and they know where to look and what to to.