I think some people overshare not in a tmi way but in a safety way. The amount of profiles people have set as public with all sorts of information on. I was browsing a fb selling page and a girl mentioned she had more pics of an item on her personal page so I went to have a look. I could see her whole profile. And it got me thinking of this thread so I had a dig (stalker ha).
If you think about it, lets say I'm a potential predator looking for someone to eventually harm. I could see that this girl was single, had a daughter, could see her daughters name, there were pictures of them both, statuses about going out and where she would be drinking and who would be watching her child. There were also statuses about what dance class her daughter went to and where it was and details of activities they were both going to. Even the name of the nursery popped up.
From all that information, I could potentially target that mum and child by gradually turning up at these places and integrating myself into their lives. I could go out drinking the same nights she does in the same places and creep into her life that way. I could happen to hang about near the activities she goes to. I could go to the park they are at and would be able to call the child over by name. I could even "friend zone" myself and become a potential babysitter after seeing how often she begs for someone to watch her child.
As a result of that girls overshare and failure to apply privacy settings to a fb profile, the door could be opened for someone deadly to just walk into her and her daughters life. In that sense I do think we can overshare in ways other than tmi about our thoughts and feelings and its quite worrying that some people may not realise quite who could be reading their profiles.