Please Help, Bitten by Facebook

Hi,
I am a 40 years old guy, happily married for 10 years and a kid. I love my family and I spend a lot of time with them trying to give a healthy and good environment for my son to grow.

All was good, until about 6 months ago, my wife's android phone's screen broke. She bought a new phone and continue using her new phone. When I got the phone repaired recently and switched on, I could see her Facebook (fb) account still logged in.

I was shocked to see that on fb, she is a part of many adult groups in which adult contents are exchanged. Adult posts, pics and videos are shared in these forums, which she enjoys and openly discusses with the members of the group. Needless to say, the language is quite inappropriate.
In fb messenger too, i could see chat histories from unknown nymphomaniacs, which she has accepted to chat instead of blocking then straight away. The chat contents too are highly inappropriate for a wife & mother to allow for.

She has added many of such members in her friends list and thus, these unknown people have access to her our personal family photos and posts. All this on her real facebook profile. I started spying over her whatsapp and realized that few of these guys and girls are on her whatsapp too.
Even though I had been telling her about dangers of social media, she chose to completely disregard my advice and indulge in such online activities and completely risking the safety, lives and reputation of the family.

Though people ask her to send her nude pics, I have not seen any nude or inappropriate pics of her sent from fb, fb messenger or whatsapp, but the possibility can not be denied of such content being shared from other applications.
Her addiction with her phone is very well observed for the past 7-8 years and now that in the past 6 months, i have found such evidences, I am not sure how long this has been going. This might be on since the time I gifted her first smartphone, 7 years ago.

Since this discovery, I have secretly monitored her fb, fb messenger and her whatsapp and has been recording screen contents. At times, I believe, she knows that she is being spied because often some inappropriate chat messages are deleted. Though she has not openly discussed with me about she being tracked (how could she !!! ), I feel she has an idea that I am tracking her.

I have not spoken to her or confronted her yet. This is because, if I confront her and show her evidences which I had been recording, she might either pick up a fight with me or immediately become apologetic. In either case, this reaction would be only to supress my confrontation and I cannot expect her loyalty to suddenly erupt just because I have confronted her with evidence. I am certain, that she would again start something similar using a different approach, more careful this time.
It's like suddenly I am seeing a totally new side of my wife, and it's extremely disturbing to know this side of hers.

I love her a lot and she too says and shows that she loves me. But then, her online behavior contradicts what she says.

Please help me. I want her back in my life with focus on the family. I do not know how to get her back. Please help me.

MY OPINION. But you do what you want or talk with other people.

This isn't what you want to hear. But maybe your guys sex life is pretty lack luster. I would question that, maybe ask her if everything is okay and that she can talk to you.
You can be upfront with her, dont fight, communicate like an adult. Who cares if she gets apologetic or defensive? If you feel it's a really important topic that needs to be discussed, talk about it.

Maybe you're overly controlling? I wouldn't care if a partner of mine had a facebook, ever, they can do as they please. Although I agree, adding random strangers from the internet from some sex related pages onto your Facebook is weird. Thats a bit of a stretch. I can understand a person's safety concerns with that.

Yea, at minimum boundaries have been crossed for you and that's not good for anyone. Trying what GLYC said is a good idea, talk to her. If you're worried that will get you nowhere, find a trusted family member or someone trusted to be there when the conversation will come up. That runs the risk of her being embarrassed and getting defensive though. All tough, but spying on her and mounting evidence is just going to add to your stress and strain and possibly add more destructive elements to this situation. Is there anyone you can think of that could be helpful to have you and your wife talk with about this situation?

Check internet history. Maybe shes been watching porn and thats all the root of this evil.

I agree with the responses here. Talk to her about it. Don't get angry.

Her behavior is just a symptom of a problem. You need to get to the root cause of the problem.

Is she bored? Unhappy? Is your sex life...mmm...just ok or nonexistent?
Does she want to talk to you or you talk to her in a certain way (bedroom talks), but was worried to tell you for fear of what you might think of her?

Again, ask her. Talk to her. Do not get mad.
And more importantly, DO NOT GET DEFENSIVE if/when she tells you what is wrong.
It might come across as your fault (or might not), but you need to be open and objective regardless.
I am not condoning her behavior. It is inappropriate.
But you want to understand why she is doing this.

You can word it the way you want, but maybe start with "I was using your phone and I noticed that you are having conversations with strangers that are concerning me. Can you tell me the reason why you are sharing this with other men instead of with me?" Or however you want to word it.

Spying on her for a while would not do you any good.
What more evidence do you need? And for what?
It's like observing someone with a fever and continuing to see how bad it gets.
Find out the cause and treat it.
The sooner, the better.

In regards to her starting up something again....but more careful this time....the only thing I can say to that is this:
You have no control over what other people do. The only person you can control is yourself.
If someone wants to do something, they will find a way to do it. And the opposite is also true.
If someone does NOT want to do something, they will find a way to NOT do it.
The only thing that you can do is set standards of what you will accept or not.