The shutdown of backpage.com, a classified website often used to advertise sex for sale, has some in London worried for the safety of the city's sex workers.

"Folks are really going to suffer very, very quickly," said Annalise Trudell, education and training manager at Anova, a London agency that provides shelter and support for women who are victims of abuse.

It's an American decision that's decreasing Canadian citizens' safety. - Annalise Trudell

Friday afternoon, backpage.com became unavailable.

A message posted on the home page says it was seized as part of an enforcement by the Federal Bureau of Investigation and other government agencies.

Political leaders in the U.S. have long accused the website of aiding in sex trafficking and child exploitation. Media reports said the company's co-founder had been arrested and charged.

But Trudell says the platform is not the problem.

In fact, she said, backpage.com keeps sex workers safe by allowing them to vet clients online, rather than working the streets.

Trudell said shutting down the website won't shut down sex workers' financial needs, which means that they'll be forced to find other ways of making money through sex work that are 'vastly less safe.'

"I get that it's an American decision in this moment, but that's having an impact on Canadian citizens and decreasing Canadian citizens' safety," said Trudell.

The London group Safe Space agrees with Trudell that the platform is not the issue. In an email to CBC News, it wrote "the problem is not backpage or other online platforms, but non consensual trafficking—totally separate from sex work."

'Void quickly filled'

This message is all that remains on the website backpage.com. (Screenshot)

London police detective Michael Hay said he found about the shutdown at about 2 p.m. Friday.

"We were looking for a possible sex trade worker who's missing in Quebec, and we noticed that suddenly the website was no longer functioning," said Hay, who is with the police's human trafficking unit.

Hay said the shutdown will likely make it harder for johns to buy sex online. But, he said that won't last long, as other classified websites become suddenly more active.

"It's going to leave a void that will be quickly filled," Hay said.

Hay said his team isn't certain what prompted the shutdown, or how long it might last.