SAN FRANCISCO - It takes a lot to make San Franciscans blush, but a video porn company has managed to do it.

Masks of all kinds hang on the Bondage Wall at the current offices of the porn film distribution company Kink.com on Mission Street in San Francisco, Calif., on Wednesday, Jan 31, 2007. [AP]

A studio that makes S&M movies recently took over a historic building that once housed the National Guard, unleashing a rare public debate about decency in a city famous for sexual permissiveness.

Kink.com, which distributes its videos on X-rated Web sites with names such as Hogtied and Men in Pain, bought the old State Armory in the Mission District for $14.5 million, saying the vacant building's dark Moorish architecture would make a perfect backdrop for fetish films.

"The basements in particular have a creepy, dungeony feel that is quite appropriate," said Kink.com founder Peter Acworth, who planned the first leather-clad shoot this week in the building where troops trained for six decades.

Acworth, 36, negotiated with the previous owner quietly to avoid a backlash until the deal was done earlier this year.

Although city planners said the studio meets zoning requirements, residents and civic leaders have reservations about allowing people to be tied up, spanked and poked with mechanical implements in the working-class neighborhood.

"While not wanting to be prudish, the fact that kink.com will be located in the proximity to a number of schools gives us pause," Mayor Gavin Newsom ¡ª who is caught up in his own sex scandal, admitting he had an affair with the wife of his campaign manager ¡ª said in a statement this week.

He planned to organize a public hearing on Kink's plans, even though city leaders acknowledge there is little they can do to stop production at the Armory.

Adding to the outrage: The building ¡ª erected in 1912, empty since 1970 and added to the National Register of Historic Places in 1978 ¡ª was sold after low-income housing advocates killed proposals to develop the Armory into offices or apartments.

The Mission Merchants Association is in a bind, with some members arguing the studio would provide an economic boost and others worried it would attract perverts, said Jean Feilmoser, president of the group.

"The mayor's office is weighing in because they are perhaps buckling to pressure, but that place has stood empty for over 30 years and all the different entities in the Mission District tried to get something going there and ended up fighting each other," Feilmoser said.

Acworth said he is tad surprised by the squeamishness. When he was a Ph.D. candidate in finance at Columbia University, he chose San Francisco as the place to build his bondage empire because "it's a fetish capital."

Acworth has hired a lobbyist, met with unions and used his British charm to try to disarm critics.

Unlike a nearby sex toy shop and a club where people have sex, Acworth's company and its 70 employees typically attract little attention and would be an improvement for a property where people made war, not love, he said.

Until he started hosting "sex positive" parties several times a month at Kink.com's current location across the street from the San Francisco Chronicle, few people knew porn was made there, he said.

"Under no circumstances would they know more about what goes on in the armory than they do about their neighbors' sex lives," he said. "The walls of the armory are so thick, the idea that anyone would have any idea what's going on inside is ridiculous."