You click an ad on FB, FB will send your Facebook ID to the advertiser. MySpace, Hi5 and LiveJournal might send data identifying the profile being **viewed **...
"But FB went further than other sites, in some cases signaling which user name or ID was clicking on the ad as well as the user name or ID of the page being viewed."
It's now a piece of cake for the advertiser to mine your personal data, the data of your friends, the data of friends of your friends. A beginning programmer will have such a script running in half-a-day or so. Yes, and unlike some of the other social networks that let you use a moniker, FB has your real, full name as well as your birth date and place of residence, allowing linkup with a plethora of other sources of data about you.
This is a marketing gold mine, FB is the owner of the mine, advertisers buy a lease on the mine.
Not only do they mine your data, they also lie about their intentions, pretending the issue was an inintentional bug. A FB spokesman:
"We fixed this case as soon as we heard about it."
Translated: We didn't intend to make your personal data (and your friends data) available to our advertisers for them to mine for advertising purposes. We actually have another business model.
Really, what is it?