According to InfoWorld report, a CA researcher has found that Facebook beacon has been reporting activities of users outside the network. In other words, no matter where you go; Facebook knows what you were doing. Something like Big Brother. But, look at the bright side; NSA no longer needs to track user activities. It can buy that data from Facebook. :-P
It is one more website on my black list.
Update: Usually I am in favor of advertising on the internet and sternly believe in that revenue model. But, this time Facebook seems to have crossed the line.