This really didn't surprise me as most people aren't tech savvy enough to know how to secure their wi-fi router. All they care about is plug it in and make it easy to connect. They don't realize the legal implications when some criminal use their connection to conduct illegal activities.
It's unfortunate that many people care little about the security of their tech devices. The conecept of it being a serious risk is simply not there and there's little that can be done other than public education. This is a novice question but is it actually safe to use HTTPS and VPN's on an unsecured Wi-Fi?
You can find out what MAC addresses are whitelisted on a router rather easily, it is in no way good security alone. Using MAC filtering plus adding in WPA2 or another encryption with a strong password is much more secure though, but like I said the filtering alone is rather easy to bypass.
The thing about open wifi, whether you are limiting MAC address connections or not, you are still transmitting your data unencrypted. Yeah, you might gain a single ms of reduced latency avoiding encryption, but I anyone can watch what you're watching if it is unencrypted. Fortunately for your bank account those pages are all typically SSL encrypted to begin with. Get some WPA up at least.