Facebook just rolled out its take on Foursquare’s "check-in" feature, which lets you tell your friends — or the world, if you like — that you’ve just ambled into a specific venue. The twist? Unlike Foursquare, Facebook Places will let your Facebook pals go ahead and check you into a place, as well — cool if you're a freewheeling social butterfly, but troubling if you're at all protective of your privacy.
Announced and launched last night, Facebook Places is only available to U.S. Facebook users for now (and it hasn't been rolled out to every U.S. Facebook user yet, so be patient), and only on the Facebook iPhone app or on mobile devices with HTML 5-compliant browsers that boast geolocation features.
Here's how it works (this will sound familiar to anyone who's used Foursquare before): If you're out on the town and you want your Facebook friends to know that you've just arrived at the Starbucks down the street, you fire up Facebook on your Places-enabled handheld, tap the Places icon, search for the venue you want to check into (you can add a venue if it isn't listed), and tap the "Check In" button. (You must actually be physically near a place to check in; for example, you can't check into the Louvre if you're sitting at home in Plano, Texas.)
Once you've checked into a place, other Facebook Places users at your location will (for a few hours, at least) be able to see that you've checked in with them, and your check-in will appear in your Facebook news feed.
What sets Facebook Places apart from other Foursquare-like "check-in" apps, however, is that you can check your fellow Facebook users into a place at the same time that you check in yourself, simply by tagging them. So, for instance, if you're strolling into a movie with, say, your friends Pete and Amber, you can check yourself in and check in Pete and Amber as well; all three of you will appear in the "People Here Now" list for that particular theater, and your check-ins will pop up as status updates. (You'll be notified the first time a Facebook friend tries to tag you through Places.)
Now, that could be handy if, say, Pete and Amber want all their pals to know where they are even if they left their iPhones at home for the evening. But what if Pete had a good reason for not wanting everyone to know he was kicking back at the multiplex — like, say, he'd been home "sick" that day, or he'd begged off from dinner at his boss's place — but you'd checked him in anyway? Uh-oh.
The good news is that Facebook has rolled out a series of new privacy controls along with the new Places feature that control who's privy to your check-ins, as well as whether your friends can check you into a given place. The bad news: Even with the new Places privacy controls, your Facebook friends can (of course) always reveal your "20" if they so choose.
If you go to Privacy Settings under the Account tab in Facebook, you'll see "Places I check in" listed under the main "Sharing on Facebook" settings, which you can set to "everyone," "friends of friends," or "friends only."
For more granular control, click the "Customize settings" link. Under "Things I share," there's a checkbox next to "Include me in 'People Here Now' after I check in"; just clear the "enable" checkbox if you don't want friends or those who've also checked in at a given venue to see that you've recently checked in there.
Don't like the idea of Facebook pals checking you into a place? Go to the "Things others share" section, find "Friends can check me in to Places" (at the bottom), and select "Disabled" from the pull-down menu. And even if your "Friends can check me in" setting is enabled, you can still remove a Places tag and/or check-in after the fact, just as you can untag yourself from a photo.
But even if you block your friends from checking you in somewhere via Places, there's nothing stopping them from blurting out, "Hey, guess who's here at the movies with me!" in a regular status update, along with a (tagged) picture of you wearing 3-D glasses — and of course, they could do so whether you're a Facebook user or not. So it goes in the age of Facebook.
For more on Facebook Places and privacy, check out the ACLU's DotRights.org site, which has an exhaustive page covering all the various Places privacy settings.
What do you think of Facebook Places? Planning on using it? Worried about the privacy implications? Fire away below.
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— Ben Patterson is a technology writer for Yahoo! News.
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