It absolutely wasn't common knowledge before Snowden. Even the suggestion would have put you firmly in the conspiracy theorist camp to most people.
Not to mention the whistleblowing on the Trailblazer Project and New York Times reporting on the "Terrorist Surveillance Program" in 2005/2006.
When the Snowden leaks came out it was not a surprise. Granted most people don't go out drinking with the people doing the spying, but even people who work at the NSA can't keep a secret, if it was even meant to be a secret.