Posting pictures of a child on facebook without both parents' consent?

[Big Swing Face]

A friend of mine has an ex boyfriend with a new girlfriend. The girlfriend is posting pictures of my friend's daughter. Is this technically illegal? The pictures are not private and can be seen by people who aren't the girlfriend's facebook friend. Does the girlfriend technically need both parents' consent to post pictures of minors? I know this sounds petty, but I am asking in technical nit-picky terms if a person can be forced to take down pictures of somebody's child if BOTH parents do not agree that it should be on facebook?

[Peanut]

Yes, she can legally be told to take the pictures down. On most websites, there is a little box that you have to tick when posting picks that says I agree not to... and it goes on to tell you things you agree not to do, one of them is having consent to post pictures of others. On most mommy websites there is box you have to tick saying that you have sole ownership of the photos and that you have the consent of the parent/s to post the pics with children in it.