MNHQ are quite good at deleting individual posts for privacy reasons, if you ask Skivvytomany.
And that's another thing.
MNHQ are, IME, on our side in this.
But lots of sites aren't. In fact, some sites/companies exist primarily as data collectors - which is why they ask you to "register free, just fill in this form with your name, address, dob, etc" before using them.
This is what Bounty are doing in maternity hospitals (the photos are just an additional revenue stream), and this is what facebook is doing.
There's now a saying, "If you aren't paying for the product, you are the product." Welcome to the information economy...