This week, a vulnerability in the OpenSSL protocol called "Heartbleed" was discovered. If none of the words you just read make any sense, here's a good explainer about how 2/3 of the internet was exposed to this security vulnerability. Worried that a website you use regularly was vulnerable? This site can help.
Lastpass, a product that lets users manage multiple passwords, has created a little applet that allows you to check if sites you use has been compromised. It could be useful if you are at all worried about the tons of personal information that might have been exposed.