This response assumes that joining all social networks is user choice. Unfortunately, we live in a world where it hurts consumers NOT to be on some networks. Li

This response assumes that joining all social networks is user choice. Unfortunately, we live in a world where it hurts consumers NOT to be on some networks. LinkedIn (which also has had a history of horrible spamming in the past) is an example - sure, you can choose not to be on it, but you'll probably get dinged by hiring managers because your credentials somehow seem less legitimate if not corroborated by LinkedIn.