The Hill is reporting that members of Congress are getting increasingly fed up with “ambush interviews” by “guerrilla-style reporters, bloggers, and campaign operatives who ambush them on video to provoke an aggressive or outraged response.” Rep. Bob Etheridge, D-N.C., is the latest to run afoul of this tactic and had to apologize after he lost his temper when journalists (or whoever they were) confronted him on the street in Washington but refused to identify themselves.

With most cell phones now capable of recording videos, and with actual video cameras getting smaller, cheaper, and more ubiquitous every year, politicians and other people in the public eye should probably operate on the assumption that there is always a video camera recording what they say and do.

But it didn’t take a technological revolution to bring ambush journalism into existence. Indeed, one of the most famous quotes of the 19th century was the result of an ambush.

William Henry Vanderbilt, who controlled the New York Central Railroad, was a vastly rich (“I would not cross the street to make another million.”) and vastly competent business executive. In 1882, he was traveling in his private railroad car on an inspection trip. He was in the middle of dinner when a young journalist named Clarence Dresser demanded an interview. According to the head of the Associated Press, Dresser “was one of the offensively aggressive types — one of those wrens who make prey where eagles dare not tread. Always importunate and usually impudent.”

There are several versions of what happened next (none likely to be wholly accurate), but according to Samuel Barton, who was Vanderbilt’s favorite nephew and who undoubtedly wanted to put his uncle in the best possible light, the conversation went as follows. “Why are you going to stop this fast mail-train?” Dresser asked.

“Because it doesn’t pay. I can’t run a train as far as this permanently at a loss.”

“But the public find it very convenient and useful. You ought to accommodate them.”

“The public? How do you know they find it useful? How do you know, or how can I know, that they want it? If they want it, why don’t they patronize it and make it pay? That’s the only test I have of whether a thing is wanted — does it pay? If it doesn’t pay, I suppose it isn’t wanted.”

“Mr. Vanderbilt, are you working for the public or for your stockholders?”

“The public be damned! I am working for my stockholders! If the public want the train, why don’t they support it?”

Vanderbilt, however impolitic his phrasing, was only telling an inescapable economic truth — one that the left didn’t grasp in 1882 and doesn’t in 2010 — about how capitalism works: the public good is served by the pursuit of private advantage.

But, of course, it was the impolitic phrasing that carried the day. “The public be damned!” was on the front page of every newspaper in the country within 24 hours. And William Henry Vanderbilt, who had not the slightest pretensions to literary talent, ended up in Bartlett’s.