Facebook Tracking | Video| 10/4/2011
When you log out of Facebook and visit any of nearly a million sites with a "like" button --
That site sends a message to Facebook that you`ve been there. "Itís the equivalent of you closing your door or hanging up your phone but a person is still there in your home following you room to room but you can`t see them." Lillie Coney/ Electronic Privacy Information Center
It`s called "frictionless sharing." Lawmakers call it an invasion of privacy.
Democrat Ed Markey and Republican Joe Barton are pushing a "do not track kids" bill in Congress.
In this letter, they`re asking the Federal Trade Commission to investigate.
The discovery comes as users adjust to other new changes. "It`s not fair to have consumers in a position to play catch up every time the company decides it wants to change something." Lillie Coney/ Electronic Privacy Information
Facebook users say they`re surprised. "That sounds awful. I didn`t know they could do that," said one person, "big brother is definitely out there."
Facebook says the tracking is part of its security - to prevent someone else from logging in as you. They say it`s not logged or used to target advertising.
Facebook also says they`ve fixed the problem. If you want to be sure, delete your browsing history or use a separate browser for Facebook.
Tracie Potts, NBC News