It seems that publishers are getting sued or threatened for possibly sharing video watching information - information that an individual has watched a video, before this individual has explicitly decided to share that information. Sharing this without the watcher's consent would be illegal.
How can I tell if video websites (like nbcsports.com/videos, discovery.com or Huffington Post) with sharing buttons/widgets are sharing what video I'm watching, before I make a conscious effort to share that information with others?