Mr. Kerzic appeared on the screen.

“The reason I was taking photos of trains is that every year Amtrak has a contest; it’s called ‘Picture Our Train,’ ” he explained.

Soon after the show was broadcast, a strange thing happened. The section of Mr. Kerzic’s Web site that dealt with Amtrak all but vanished. His lawsuit was settled, and as a condition of the deal, he had to remove his writings about the episode. Now his page on Amtrak — at duanek.name/Amtrak/ — contains two words: “No Comment!”

Mr. Kerzic and his lawyer, Gerald Cohen, both said they couldn’t talk about what had become of the Web pages describing the arrest and his commentary about it. Carlos Miller, a photographer and blogger who followed the case, reported that Mr. Kerzic received a “five-figure” settlement.

But how could Amtrak — the national railroad, whose preferred stock is owned by the American public and whose chief executive and board of directors are appointed by the president and confirmed by Congress — require that a Web site criticizing the railroad be shut down as a condition of settling a lawsuit for wrongful arrest?

What qualifications does Amtrak have to function as a censor?

“Our policy has been and continues to be that ‘Amtrak does not comment on civil case settlements,’ ”Clifford Cole, an Amtrak spokesman, said in an e-mail message. “We would not have any more to say on this matter.”