With new Facebook search, there’s nowhere to hide

Gun owners in New York State recently freaked when a local newspaper published their names and addresses online. It’s all public information, the ­paper declared. But never before had the data been made so available, critics replied. Perhaps the paper had made public information too public?

Which brings us to Facebook and its fun, fascinating, and worrisome new search service. Currently available only to a relative handful of Facebook’s billion registered ­users, the new service lets you quickly find out quite a bit about your Facebook friends, or complete strangers. It’s stuff you could find already, with diligent research, but soon it will take a few keystrokes, not unlike how the New York newspaper made the names of gun owners so easily available.

Facebook’s new search is a clever idea, but not without peril. It can make sensitive information too easy to find. Indeed, the New York newspaper pulled the gun database from its website, after two gun owners had their homes burglarized.

So even before Facebook users begin enjoying the new search tool, they should make sure it won’t reveal too many of their own secrets.

Facebook’s new service bears an awful name — “Graph Search.” This refers to the ­“social graph,” Facebook’s term for the complex connections among you and others online. If you drew all those connections onto a (rather large) piece of paper, the resulting spiderweb is your ­social graph. Simply by using Facebook, you’ve already built up quite a large one. It gets much bigger when you add the places and products you’ve chosen to “like” using Facebook’s popular rating system. Graph Search lets you quickly untangle this digital spiderweb.

With old-school Facebook search, you could look for ­people who like Boston, or who had attended Harvard, or rooted for the Chicago Bears. But you’d run each search ­separately.

Now, I can run a single search and find Harvard ­alums in Beantown who love the Monsters of the Midway. Or perhaps you’d like to date a single woman who hangs out at a popular sports bar in Quincy. Facebook found 10 of them. Good thing I’m married.

I think Facebook is glancing over its shoulder at the Google Plus social network. Once widely derided as a flop, Google Plus now boasts half a billion registered users and 235 million regular visitors. Pretty good for a service I ­described last March as “lifeless.” And quite good enough to pose a real challenge to ­Facebook.

In response, Facebook has already teamed up with Microsoft Corp.’s Bing search service. Run a search on Bing, and if your Facebook friends have anything to say on the subject, you will see their comments on the side of the page. But Graph Search drills far deeper, helping you track the collective wisdom and folly of millions of Facebookers.

For now, you can only search a limited inventory of items, including published photos, places that users have visited, or things they’ve ­chosen to like. For example, when I typed “pizza places my friends like.” I got about 70 choices, accompanied by a map of the United States showing their general ­location. A drop-down menu let me hone the search further. I could ask for Boston restaurants, or look for a recommendation from a specific friend.

On the other hand, when I asked for Boston restaurants that are popular with Facebook users from Italy, I got only one result — a place that serves Asian food.

Searching by Facebook likes is a dicey proposition. Many fans of a product don’t click its “like” button; others “like” something merely as a way of bookmarking the site, not because they’ve ever actually tasted the food or seen the movie; still other “likers” will change their minds, but forget to change their votes.

Searches based on Facebook likes will always be as spongy and unreliable as human whims and passions.

So Facebook Graph Search provides endless opportunities for mischief and abuse. Try asking for “people from China who like Falun Gong,” a religious movement whose followers are routinely imprisoned in China. My search turned up dozens of names; their next ­visits home could be rather unpleasant.

Facebookers have good reason to fear Graph Search will compromise their privacy. Luckily, there’s no law requiring you to publicize your most sensitive thoughts. And if you already have, Facebook last month made it easier to tidy up your earlier blunders. A new privacy control page will let you quickly conceal embarrassing photos and likes.

Facebook plans to gradually open its new search service to all members in the months ahead. It also plans enhancements that will enable even deeper searches. So if you’ve got something to hide, get busy.