's another example of why user control needs to be the default in Facebook . '' In the last few months , scrutiny of the privacy practices of the Internet 's second most popular Web site has reached an all-time high , with politicians threatening probes and privacy activists calling for formal investigations . In response to the outcry , Zuckerberg convened a press conference last week at Facebook 's Palo Alto , California , headquarters , where he pledged to make privacy `` simpler . '' For its part , Facebook told CNET on Tuesday that the information about who viewed what pages with a Like button is anonymized after three months and is not shared with or sold to third parties . A representative acknowledged , however , that the current privacy description of Facebook 's social plugins `` is not as clear as it could be , and we 'll fix that . '' Facebook 's FAQ says : `` No data is shared about you when you see a social plugin on an external website . '' No mention of this data-sharing appears under the `` Information from other websites '' section of the company 's
-LRB- CNET -RRB- -- When Facebook Chief Executive Mark Zuckerberg recently announced a `` Like '' button that publishers could place on their Web pages , he predicted it would make the Web smarter and `` more social . '' What Zuckerberg did n't point out is that widespread use of the Like button allows Facebook to track people as they switch from CNN.com to Yelp.com to ESPN.com , all of which are sites that have said they will implement the feature . Even if someone is not a Facebook user or is not logged in , Facebook 's social plugins collect the address of the Web page being visited and the Internet address of the visitor as soon as the page is loaded -- clicking on the Like button is not required . If enough sites participate , that permits Facebook to assemble a vast amount of data about Internet users ' browsing habits . `` If you put a Like button on your site , you 're potentially selling out your users ' privacy even if they never press that button , '' says Nicole Ozer , an attorney with the ACLU of Northern California . `` It