Google has plausible deniability here: "Unlike Facebook, which hides data from Google, or Twitter, which directs Google not to follow most of its links, Google+

Google has plausible deniability here: "Unlike Facebook, which hides data from Google, or Twitter, which directs Google not to follow most of its links, Google+ data is immediately and fully accessible to the company that built it." Neither can turn around and argue about monopolistic practices because google can say that twitter and facebook refused to give them data (and they would use those sources if permitted)