CLEVELAND, OH (WOIO) - Can you keep a secret?
Well, that's the point if you want to be a member in some social media circles.
Facebook has tens of millions of groups, many of them Secret Groups that you don't even know about.
Cleveland 19 News reporter Sia Nyorkor says some of the members in these groups are so protective, they wouldn't even talk about it.
She's been uncovering "The Secret World of Facebook Secret Groups" and has this reveal.
They say it's kinda like the movie, "Fight Club."
"First rule of Fight Club, you do not talk about Fight Club, the second rule of Fight Club, you do not talk about Fight Club," said the actor, Brad Pitt.
Which makes it tough to find out what some Facebook secret groups are all about if you're not even supposed to know about them.
"In general these secret groups are pretty secret. Facebook goes to great lengths to protect these groups and thinks about them pretty carefully," said Cliff Lampe, Associate Professor of Information, University of Michigan.
There are three types of Facebook groups: open, closed and secret. There are tens of millions of them with no breakdown of how many are secret---those groups aren't even searchable and a member has to invite you to join. Topics range from parenting to health & fitness to more personal things like sex and relationships.
Professor Lampe, studies social media and finds it's one reason why some people crave the secrecy within these groups.
"That's why I think a lot of people rejected you or wouldn't talk to you on camera not necessarily to protect themselves but because they have an obligation to themselves and the group members. Because they realize everyone is taking a risk and being vulnerable in these groups and they wouldn't want to betray that vulnerability that people sharing have with each other," said Professor Lampe.
"But when you're on the internet, is anything really secretive or private," asked Cleveland 19 News reporter Sia Nyorkor.
"Yes, I think the common narrative is that anything you say online could be leaked and you know under an aggressive hacker attack yes people could turn into your computer, get the cache or if somebody hacked into Facebook they might be able to get that data and of course Facebook has a huge incentive not to share it with anybody," said Professor Lampe.
Facebook says one of the more "visible" secret groups is "Girls Night In" out of Los Angeles, which was documented on Fusion. It has about 1500 women that one member describes as a "Digital Sisterhood." The rules of membership are in black & white: "Everything posted in this group is private, top secret and should remain in this group. Sharing info or posts from this group with others will result in expulsion from the group and public shaming."
Jodie Beveridge says she started her own Facebook group after another group (which shall remain anonymous) refused to let her husband in.
"Avon I Don't Know is a direct result of not being able to get in the know for my husband," said Beveridge, creator.
Beverdige says there are about 200 people in her group and they've never rejected anyone for membership, it's all in fun.
"You will never find a garage sale posted on our website or we can not tell you what's being built in Avon or when it's going to open. We have no connection with the city of Avon or no contact. It's strictly people making really stupid jokes about the things they see in their homes and their communities,' she said.
Research shows these groups have become increasingly popular over the last few years. More than a billion people use Facebook groups every month and it's a top feature.
Professor Lampe says they allow people to interact without exposing themselves to everyone.
"There's kind of a group obligation that forms so when you join one of these groups, you're kind of agreeing to think about the health of the group, not just your own personal benefit," he said.
And while there will always be mystery surrounding these Facebook secret groups, it's transparent that most members will honor the code.
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