Bull and Williams (Photo: Alastair Grant/AP)

In Soho, London last week, James Bull (23) and Jonathan Williams (26) were asked to leave a pub after kissing each other. First by a man claiming to be the landlord, who said their display of affection was "bothering" him; later by a woman in staff uniform, who said she was the landlady and found their kissing "obscene." Williams turned to Twitter to register his discontent.

Within hours, Williams' tweet had been re-tweeted hundreds of times, spurring a Kiss-in event in front of the pub, which closed its doors early to thwart off protesters.

Photo used for event on Facebook

The Kiss-in event had been announced on Facebook, but first a photo of two men kissing used to promote the event was removed by Facebook; then the entire event was taken off, with this email as an explanation:

Hello,

Content that you shared on Facebook has been removed because it violated Facebook's Statement of Rights and Responsibilities. Shares that contain nudity, or any kind of graphic or sexually suggestive content, are not permitted on Facebook.

This message serves as a warning. Additional violations may result in the termination of your account. Please read the Statement of Rights and Responsibilities carefully and refrain from posting abusive material in the future. Thanks in advance for your understanding and cooperation.

The Facebook Team

But last Friday, more than three hundred people gathered in front of the pub, locking lips in defiance.