The business social network LinkedIn and the dating site eHarmony say millions of their users' passwords were stolen -- and have been leaked on the Internet.  HLN's Jennifer Westhoven says the companies haven't given many details, but the takeaway here is: "Change your password."

LinkedIn posted this Mashable article on its site. It that says that more than six million passwords were leaked. 

The big concern is, if you use the same password for multiple sites, thieves can use it to break into other accounts. Gmail, Amazon, your bank account ... any account that shares the same password as your LinkedIn profile could be at risk. If you use one password on several websites, consider changing them all -- quickly!