If your kids see you jostling to get the best shot of the most mundane moments of life, just so that you can post a picture of it on your Instagram account, they'll follow suit. If you post inappropriate images or comments on social media, the will be seen by your children, guaranteed. Limit and moderate your own social media activity.
Parents: Facebook is not in the business of raising my child, nor should you expect Facebook to raise yours. It is not the responsibility of Twitter to make sure my child behaves well online -- it is my responsibility to make sure my child behaves in any environment. If we want major change, it will not come from laws or banning people from websites; it will come from parents, communities, and schools to engage in dialogue and education to raise children who have an understanding of digital citizenship and accountability for their online and offline actions, because accountability and respect still matter.
Last Thursday, my almost-eight-year-old son's innocence was forever tainted when he discovered, through a Google search, bare-naked ladies (not the talented Canadian singing ones), on his iPod touch. We had a 'situation' here and I needed to deal with it. I didn't want my son to think he was that bad or a deviant.