Two of the biggest deepfake pornography websites have now started blocking people trying to access them from the United Kingdom. The move comes days after the UK government announced plans for a new law that will make creating nonconsensual deepfakes a criminal offense.

Nonconsensual deepfake pornography websites and apps that “strip” clothes off of photos have been growing at an alarming rate—causing untold harm to the thousands of women they are used to target.

Clare McGlynn, a professor of law at Durham University, says the move is a “hugely significant moment” in the fight against deepfake abuse. “This ends the easy access and the normalization of deepfake sexual abuse material,” McGlynn tells WIRED.

Since deepfake technology first emerged in December 2017, it has consistently been used to create nonconsensual sexual images of women—swapping their faces into pornographic videos or allowing new “nude” images to be generated. As the technology has improved and become easier to access, hundreds of websites and apps have been created. Most recently, schoolchildren have been caught creating nudes of classmates.

The blocks on the deepfake websites in the UK were first spotted today, with two of the most prominent services displaying notices on their landing pages that they are no longer accessible to people visiting from the country. WIRED is not naming the two websites due to their enabling of abuse.

One of the websites with the restriction in place is the biggest deepfake pornography website existing today. Its homepage, when visiting from the UK, displays a message saying access is denied. “Due to laws or (upcoming) legislation in your country or state, we are unfortunately obligated to deny you access to this website,” the message says. It also shows the visitor’s IP address and country.

The other website, which also has an app, displays a similar message. “Access to the service in your country is blocked,” it says, before hinting there may be ways to get around the geographic restriction. The websites do not appear to have any restrictions in place when visiting from the United States, although may also be restricted in other countries.

It is not immediately clear why the sites have introduced the location blocks or whether they have done so in response to any legal orders or notices. Nor is it clear whether the blocks are temporary. Messages sent to the websites through email addresses and contact forms went unanswered. The creators of the websites have not posted any public messages on the websites or their social media channels about the blocks.

Ofcom, the UK’s communications regulator, has the power to persue action against harmful websites under the UK’s controversial sweeping online safety laws that came into force last year. However, these powers are not yet fully operational, and Ofcom is still consulting on them.

It’s likely the restrictions may significantly limit the amount of people in the UK seeking out or trying to create deepfake sexual abuse content. Data from Similarweb, a digital intelligence company, shows the biggest of the two websites had 12 million global visitors last month, while the other website had 4 million visitors. In the UK, they had around 500,000 and 50,000 visitors, respectively.