It is arguable that the primary purpose of Facebook originally was to allow two friends to communicate over a third person's website. There was no "news feed".
Is this a "social network" or is it "social media"?
Later the website became a means to broadcast "news".
Is it a "social network" or is it "social media"?
Later the website became a means for third parties other than Facebook to broadcast advertisements to specific users of the "network".
Is it a "social network" or is it "social media"?
Why might this distinction matter?
This is a quote from Van Jacobsen's 30 August 2006 tech talk entitled "A new way to think about networking":
"The raison d'etre of today's networking, both circuit switched and TCP/IP, is to allow two machines to have a conversation.
The overwhelming use (>99% by most measurements) of today's networks is for a machine to acquire named chunks of data (like webpages or email messages).
Acquiring named chunks of data is not a conversation, it's a dissemination (the computer equivalent of "Does anybody have the time?")"
What is Facebook?
Is it particular communications between two friends? Is it a "network"?
Is it dissemination? Is it "media"?
Is it both?
Does Facebook communication between friends upset the traditional media? Does it "threaten democracy"?
Does Facebook dissemination upset the traditional media? Does it "threaten democracy"?
The tech talk cited above discusses why in the case of dissemination the data matters, not the supplier.
In the case of dissemination it is desirable that data being disseminated must be trustworthy. Once this is achieved it should not matter the source from which the reader obtains it (whether via a Facebook page being surveilled by Facebook, or via some random address elsewhere on the internet).
The talk describes how this might be accomplished.