Women eat on a Circle Line Underground train in protest at the 'Women who eat on tubes" website on April 14, 2014 in London, England. (Oli Scarff/Getty Images)

LONDON -- They had come to eat. They had come to ride the Tube.

Most of all, they had come to deliver a sharp poke in the ribs to the men who photograph women who eat while riding the Tube.

The unusual protest that unfurled Monday as a Circle Line subway train wound its way through central London was the product of an unusual controversy.

For days, Londoners have been waging pitched battles. Was the Facebook page Women Who Eat on Tubes -- featuring surreptitiously taken photos of, well, exactly that -- an example of self-expression worth defending, or a crude and troubling violation of privacy? Was it high art, or misogynistic trash?

Or was it just creepy?

"It's really creepy," said Flo Cullen-Davies, 20.

Cullen-Davies had turned out Monday with dozens of like-minded Londoners -- some old, some young; many women, a few men -- to publicly demonstrate her pique through a picnic.

By eating publicly and without apology, they would defy the casual voyeurism and less-than-casual shaming that they say drives traffic and contributions to the Facebook page. Instead of getting caught mid-bite by a cleverly concealed camera phone, they would proudly mug for the news media.

At lunch-time, the picnickers packed into a Circle Line train, and out came the food. Apples and rice cakes. Sandwiches and potato chips. Lots of bananas.

Once the train started rolling, the moveable feast began.

"Eating on the Tube is not something that should be condemned or ridiculed," said Lauren Bush, 22, in between bites of a Reese's Peanut Butter Cup. "The age of social media just provides another way for women to be objectified. We've got to stop that." Under normal circumstances, Britons don't tend to be overly concerned with privacy. Revelations of mass government surveillance come and go without eliciting more than a shrug. Closed-circuit television cameras loom over every street corner, and few complain.

But the Facebook page, which was recently made accessible to members only, touched a nerve. Although the site has been around since 2011, it's recently grown in popularity, with nearly 25,000 members as of Monday afternoon. It's also earned greater notoriety, with blatantly offensive captions such as "Three little pigs."

The site's founder probably didn't help matters when he compared his creation to wildlife photography.

"At its truest form," Tony Burke, a 39-year-old filmmaker, told Britain's Daily Telegraph, "it should cherish its subjects in the way a wildlife photographer cherishes a kingfisher in a river."

Speaking to BBC radio last week, Burke elaborated, saying that the site was intended as "an observational, artistic, photographic study of human behavior." It was created, he said, based on his theory that more women than men ate while riding on London's Tube -- which, unlike other subway systems, has a nearly-anything-goes approach to public consumption.

Women standing in a Circle Line Underground train in protest at the 'Women who eat on tubes' Web site on April 14, 2014 in London, England. (Oli Scarff/Getty Images)

But Burke's art was lost on Lucy Brisbane Mckay, the 21-year-old student who jousted with Burke on the radio and who organized Monday's picnic.

"There are 20,000 people out there watching, waiting for you to eat, to put it up on the page," said Mckay, who said she stopped eating on the Tube because of the site. "As much as people may say it's not the biggest problem in the world, and they are right, it is weird that you have to change your behavior."

Cullen-Davies said she found out about the site a week ago, and has been on guard while riding the Tube ever since.

"I used to have an eating disorder, and I'm aware of how women, even more than men, are made to feel needy and shameful around food," she said. "If it were just "Humans Eating on Tubes," I still wouldn't support it. But at least it wouldn't have that same misogynistic aspect."

Still, not everyone was incensed -- even among the picnickers. Suzanne Noble, 53, was among those who turned up Monday to eat on the Tube, and she said it was her 22-year-old son who had encouraged her. The same son who's a devoted follower of "Women Who Eat on Tubes."

"To be honest," she said, "I think it's all just light-hearted fun."