His cellphone conversations were overheard by a fellow train passenger, who let the world know via Twitter.
"On Acela: former NSA spy boss Michael Hayden just ended last of handful of interviews bashing administration," Tom Matzzie tweeted Thursday.
Matzzie, former Washington director of MoveOn.org., tweeted that Hayden was sitting behind him "blabbing on background as a former senior admin official."
"I feel like I'm in the NSA. Except I'm in public," Matzzie tweeted.
He feared that he might get caught.
"On Acela: phone ringing. I think the jig is up. Maybe somebody is telling him I'm here. Do I hide?"
"Just passed Philly. No rendition yet," he tweeted.
Matzzie told the Los Angeles Times Friday that Hayden, who was NSA chief from 1999 to 2005, had "no expectation of privacy" in a public place, adding the former NSA chief was sitting about 7 or 8 feet behind him, "talking very loudly.''
Hayden's office apparently caught wind of the tweets and alerted the former NSA chief, who took it well, posing for a picture with Matzzie, 38, who runs a renewable energy company.
Matzzie told The Times that Hayden walked over to him and asked if he would like an interview.
"I said I'm not a reporter," Matzzie said. "He said, 'Everybody is a reporter.'"
Hayden, who also was
"I actually said these are very difficult issues. I said I had political guidance, too, that limited the things that I did when I was director of NSA. Now that political guidance is going to be more robust. It wasn't criticism."
After meeting Hayden during the ride, Matzzie tweeted, "I just had a very nice conversation with Michael Hayden. He was a gentleman and we disagree."
The incident came as the U.S. government’s surveillance has come under scrutiny, drawing anger from European allies amid reports that American intelligence agencies may have tapped German Chancellor
As for Hayden's conversations, Matzzie tweeted the obvious: "This was not the quiet car."