( CNN ) -- Facebook on Monday appeared to have quietly unveiled a new feature designed to let people see which Facebook users are nearby at any given time . By Tuesday , however , the feature seemed to have been pulled from the Internet . The company called the feature `` Find Friends Nearby , '' and on Monday it was available through Facebook 's mobile apps and website despite the fact that it had n't been formally announced . The blog ReadWriteWeb dubbed the feature a `` stalking app '' because it could open people up to potentially awkward or threatening interactions with strangers on the social network who know you 're nearby . To test out the feature on Monday , Facebook users could go to fb.com/ffn in a browser , or follow this path in the Facebook 's mobile apps : menu > apps > find friends > other tools > Find Friends Nearby . Surprise ! Teens are sneaky online . Facebook users had to opt in to the feature by going to that site , otherwise their profiles would not appear in a list of people who are nearby . The blog TechCrunch first reported on the feature Sunday after a non-Facebook developer tipped off the site to the feature 's existence . In a comment on that site 's post about the new feature , Facebook developer Ryan Patterson , who says he developed Find Friends Nearby , described how he hopes the app will be used : . `` For me , the ideal use case for this product is the one where when you 're out with a group of people whom you 've recently met and want to stay in contact with . Facebook search might be effective , or sharing your vanity addresses or business cards , but this tool provides a really easy way to exchange contact information with multiple people with minimal friction . '' A Facebook spokeswoman declined to provide additional information . `` We are constantly testing new features but have nothing more to share at this time , '' she wrote in an e-mail to CNN . Reactions to the news were mixed in the tech blogosphere . The site Gizmodo found the new feature to be potentially useful -- and dangerous . `` You meet a cute somebody at a concert , you 're like , 'Hey , we should be Facebook friends , ' and they 're like 'OMG , totes ! ' Then rather than having to spell your names and search around , you 've got a much smaller group of people to choose from . I guess that 's great , right ? '' Brent Rose wrote on that tech news site . But Rose added : `` Sure , it 'd be great to easily add a contact quicker , but imagine this : some creeper has been molesting you with his/her eyes all night . She opens the app , can kinda recognize your face from your profile picture , and now said creeper knows ( your ) name and possibly some of your personal info . '' That would be the downside . Others said the app simply is n't ready for prime time . The blog Engadget called the app `` fairly primitive , '' and The Next Web said it amounts to `` nothing more than a parlor trick at this point '' since other location-based friend finders have n't caught on with the general public despite their buzziness in tech circles . Facebook recently acquired a company called Glancee , which did something similar to the Find Friends Nearby feature . So there 's speculation that the company 's technology may have contributed to the new Facebook feature . Patterson , however , the Facebook developer , wrote on TechCrunch 's post that he created the feature during a hackathon . Other similar mobile `` social discovery '' apps include Highlight , Banjo and Sonar . Some of these apps will also show you nearby friends of friends or even strangers who share your interests , based on your social-network profile . It 's unclear exactly how much information the Find Friends Nearby feature gave away . On Monday , users had to log into that site intentionally to see a list of people who are nearby , and that list of people appeared to be quite limited . Also to be determined is how large of a radius the feature employed . Did it search for people who are within eyeshot of you ? Or within a mile ? Let us know what you think in the comments section . On Monday , we were n't able to interact with anyone -- friendly or otherwise -- who was nearby .
NEW : Facebook appears to have pulled the 'Find Friends Nearby ' feature . The feature uses phones ' GPS to show which of your friends are near your location . Blog ReadWriteWeb already has dubbed the feature a `` stalking app '' It appears Facebook users must opt in to the feature , which may allay privacy concerns .