Open source intelligence has been around for a while. Investigative journalism is one form. Competitive intelligence is another. Espionage may be a third.
Where all this comes into the picture is social media. I recently moderated a very heated debated among people working for rivals in the analytics niche. The row got bad and personal.
Tempers only cooled when I reminded everyone that the way they treated others in the thread, including their competitors, the way they conducted themselves in the face of challenge, argument and criticism, said more about them and their companies than any RFP ever would.
Social media is the biggest, richest and most easily accessible source of open intelligence, here for the taking.