Earlier today, news broke that a file containing over 400,000 usernames and passwords, apparently stolen from a Yahoo service by a hacker collective, was posted online. The passwords appeared in “plaintext” (or “cleartext”), meaning they were unencrypted. A security site that analyzed the posted data determined that the accounts were not just with Yahoo but also with other online services, including Gmail, AOL, Hotmail, and others, as well as a number of .GOV and .MIL addresses