Where Should One Wear One's Heart?

I belong to a well known social media site. It never ceases to amaze me all the personal facts people willingly post about themselves and their lives on this site.

More than a few times (in fact, at least a couple times a month), someone (generally somebody younger) posts about a break up - a relationship over, a heartache begun. I know this is their way to reach out, to (hopefully) have others reach out to them. The maternal side of me feels their loss, their heartfelt pain.

The older, cynical part of me, however, wonders why they have announced this very personal fact for all the world (or at least their circle of friends, which is, in essence, their world) to see. I can't remember the last time I was able to wear my heart out on my sleeve like that, and I am (or have been in the not so distant past) a fairly trusting person.

I guess the repeated hurt of break ups brings about this cynicism, this lack of trust. Even in my new relationship, I tend to keep my heart hidden just a bit. I wonder which is better and which is worse?