Vicki Kennedy in 2009. (Chip Somodevilla/Getty Images)

When is a public speech to hundreds of people not public? When it’s “off the record.”

Vicki Kennedy, widow of the late senator Ted Kennedy, gave the keynote last week at the Wendt Center dinner, a fundraiser for the grief counseling facility. Minutes before she took the podium to discuss her husband’s last year of life, organizers told us her remarks were off-limits to the media — even though there were 350 other folks in the room.

Kennedy told us Saturday, “The center felt they were acting in my interest to ask that it not be quoted. . . . I appreciate their kindness and warmth to me as I shared my personal story.”

Declaring a public event “off the record” is an increasingly common phenomenon, especially in political Washington. What once was an honor-bound agreement between an individual reporter and source has devolved into a unilateral ban on writing anything uttered by a VIP speaker.

Zuckerberg on his Cambridge visit last week. (Darren McCollester/Getty Images)

Plouffe in 2009. (Lionel Cironneau/AP)

“It’s been an ongoing problem, and it’s worse with Twitter, Facebook and all the ways we connect,” said Rick Blum, coordinator of Sunshine in Government Initiative, which calls for all speeches by government officials to be open for coverage. These days anyone with a cellphone can tape any speech — or selective, misleading portions. (Remember Shirley Sherrod?) Banning reporters, he said makes it difficult to objectively know what powerbrokers are really saying.

So what’s going on here? One theory, he said, is that speakers want to protect themselves from the poorly worded sentence that might come back to haunt them.

“More troublesome,” Blum said: Others are cynically tailoring their remarks to specific groups.

George W. Bush in Denver last month. (Andy Cross/AP)

Another factor is economic: The lecture circuit can be lucrative, and who wants to give it away for free? Many speakers have only one really socko address they deliver over and over. If it got reported, it might become stale.

Washington Speakers Bureau and the Harry Walker Agency — two major bookers in the paid-speech business — did not respond to requests for comment, on or off the record.