By now everyone should know that two-factor authentication via SMS is outdated and insecure. But in case anyone needs a reminder, here it is: Metro Bank in the UK was recently the victim of something called SS7 attacks, which basically allow anyone with access to reroute text messages and calls as they please, as well as track the location of a compromised phone. This is far from the first time this has happened, and it seems European banks are more at risk than US banks.