A computer security firm has found evidence that a Russian cybercrime gang has stolen some 1.2 billion Internet passwords and user names. At this point, we don’t know which sites the passwords are connected to. But given the size of the possible theft, this is something you should take time to respond to as soon as you can, by updating your passwords and making sure they are secure. Your losses on charges to a stolen credit card are limited by law to $50, and they are capped on debit cards if you report a problem promptly. But the latest case may merit more caution because losing a password to a website that holds your personal data can be much harder to recover from. So click here to learn about how to prioritize your response. This means Google, Yahoo, Facebook, Dropbox, Twitter, Apple iCloud, Twitter—any place where you communicate with people and leave valuable data.