The new functionality allows a user to search, as an example, for "Chinese restaurants in New York City visited by my friends," or other criteria. Uploaded content that is made public is searchable by anyone, while content limited to your friends is only searchable by them. Some information that isn't available internally on Facebook can be searched on the Web through a partnership with Microsoft 's Bing search engine.

In its announcement Tuesday, Facebook noted that Graph Search "makes finding new things much easier, but you can only see what you could already view elsewhere on Facebook."

'Privacy in Mind'

Having been burnt many times by adverse member reactions, the management of Facebook is certainly aware that some users will have privacy concerns. The company said that it "built Graph Search from the start with privacy in mind," but some observers are aware that Facebook has continually revised -- and sometimes complicated -- its definition of privacy and the tools needed to protect it.

One issue, for instance, is that a photo of you in, say, a less than flattering light in a given restaurant can be searchable by all if someone uploaded it and made that public.

A user could untag oneself from that photo, or request the person who uploaded it change its access settings. As Graph Search rolls out, Facebook is asking that users review access settings to their personal content. It points out several tips for doing so, such as the audience selector through which a user can see which things are shared, the activity log to see and review what's been hidden from the timeline, and the About section to edit info about you.

Graph Search is in beta and, for the moment, participation requires an invite. The company said that as it rolls out, participating users will see a prompt encouraging them to review the access settings for their content.

Ancient Content

Some privacy advocates note that, even though content is as limited or as accessible as it ever was, now there is a tool that gives greater and easier access to that content.

The Electronic Frontier Foundation's Adi Kamdar, for instance, told news media that content that users had made available to friends or to the public prior to Graph Search was "thought to be too hard to find," but now it can be found easily. This can mean, for instance, that an ancient and potentially embarrassing "like" in your past comes back via someone's search.

Previous changes in functionality on Facebook have prompted massive member backlash, but the reaction among privacy advocates so far indicates that the level of unease about Graph Search may not rise to that point.

The most likely reaction, according to the Electronic Privacy Information Center and other Facebook-watchers, is that members will now be incentivized to be more aware of the access settings for all of their content, and more encouraged to better manage their content history.