It is very tempting for people to share things on there, that's why you see so many people posting every single little detail about their daily lives. I am the type of person who is an open book. My friends know everything about me and I hold nothing back.
It's easy to say, "don't post it." But it simply did not work for me. If I was upset, I would post about it--and then be humiliated later when everyone knew every detail of the latest problem I was having. I'm a very emotional, passionate person. I can't control myself and also suffer from some emotional issues. When I had Facebook, I found myself unable to stop myself from sharing every detail about whatever I happened to be going through that day. Most times, I did this hoping for some type of support or attention from people I cared about. But most times, I'd go ignored. And like I said in my other post, my friends who were actually there for me were there for me outside Facebook. I already had support. So why did I feel the need to seek it from these random acquaintences, long-distance family members and other people who were not in my life outside Facebook? I don't know the answer to that, but it caused me a lot of pain. It seemed that every day of my life I was upset about something on Facebook. This went on for more than a year.
Yes, it is a person's choice what they post, and for some people, that might not cause any problems. But it's more complicated than it being the person's choice what they post. Everything about Facebook is designed to draw you in and get you stuck there. It has a nasty energy about it and they do take your personal information and use it for other things--it says right there in the contracts that they make you sign to get started.
It tends to bring out the worst in people, too. Like I said, for some people, this probably won't cause any problems. Some people never have social issues in life anyway. They go through their whole life with the same circle of friends and relatively no drama. My life has never been that way. I've never gotten along well with most people. I was bullied terribly when I was young. I just don't like people, honestly. That's what it comes down to. So being immersed in up-to-the-minute communication with every person I'd ever met in my life all at once was not a good situation for me at all.