The only one that has anything with a password is my 15 yr old. Yes I know the password to his FB and to his email. He never gets into his email.. neither do I. But his facebook I scan it about once a week. I don't read everything, just scan it. I check to see who he has recently added as new friends. I will ask him sometimes how he knows a person or what ever.
I didn't do it as often until someone tried to add him as a friend and it was a pic of a girl in her about 20's wearing a thong and had her arm over her very large chest bent over so you got full view of her backside and could see enough of her chest to wear you didn't have to guess what they looked like. I reported her and emailed her back a very "lovely" message and reported her to the cops after I printed out the email that said that she would like to meet him and make all of his fantasies come true!! ( he brought it to my attention)
I don't go into his phone unless Im trying to figure out what is making him in the mood and act the way he is when he is acting out. Usually its just he got turned down by a girl. But at least I know.
One time I was scanning his FB and seen a friend say he was done with his life and was leaving... then I dug farther, I read all the comments he was making, looked into his email and seen more messages along that line... then I went to his phone and read all of the texts. I woke my son up at midnight and explained what I did, at first he was mad but after I explained why he was ok and we talked about depression and suicide. My son kept saying he is just depressed and wont hurt himself. I told him how everything he was saying is a cry for help. It was great to see my son trying to help him, he was doing everything right except coming to me or a teacher. The next day I called the school and talked to the counselor and asked if that kid was in school... he was not. I told her everything I found and she knew he was down and out but not to that point. The school called the parent who didn't know the kids wasn't in school, the parent, the cop and the counselor all went to the house and the child had taken some pills. Thankfully the found him in time. He got his stomach pumped and got into counseling and is better today.
So my point is that kids aren't ready to handle all situations yet and I don't feel I am invading on his privacy or breaking any trust, but more looking out for them in today's age of technology. My son doesn't have a problem with me doing it, he is open to me about things and like he said if he has nothing to hide why should it matter.
My son can also get into mine and my husbands accounts also. All of our passwords are saved on the computer to where any of us can get into any of them.