After reading the following article I feel better about not posting my family tree on the face book!
"Researchers are claiming Facebook's Beacon online ad system is even more intrusive when it comes to privacy matters than protesters against the technology might have thought initially.
On Friday, Stefan Berteau, a senior research engineer at Computer Associates' Threat Research Group, published findings that reveal Beacon reports member activities on third-party partner sites even if Facebook users are not logged in, and even if members have declined to opt in to the Beacon program.
"It can happen completely without their knowledge," Berteau said in his report. "The bottom line is that Facebook is materially misrepresenting the privacy impact of their Beacon program, and presenting users with the appearance of control over their information when in fact they have almost none.""