Next month, the UK is scheduled to introduce its so-called “porn block,” a controversial piece of legislation that aims to block access to online pornography for those under the age of 18. But new research suggests that most UK citizens don’t even know the law is on its way.

According to a survey from YouGov, 76 percent of Britons are unaware that the porn block is scheduled to take effect in April. Unsurprisingly, those who said they “never” watched porn were most likely to be in the dark. (In this group, 85 percent said they didn’t know about the law.) But even among the most frequent porn watchers (those who said they watched porn “every or most days”), awareness is low. Less than half of this group (47 percent) said they knew about the incoming legislation.

Once they were told about the law, though, most were in favor. The survey found that a significant majority — two-thirds of the public, or 67 percent — support the law. However, only one-third of respondents (34 percent) thought it would be effective.

Experts on the matter definitely side with those predicting failure.

The policy, which has been in the works since 2017, has been widely criticized by a diverse array of academics, pornographers, and internet rights advocates. They say that not only will the law be ineffective, but it will create new privacy problems, transfer regulatory power to big porn companies, and push children toward unsafe sites.

The legislation means any adult site operating in the UK will have to check that visitors are older than 18. These checks will be done by verifying a credit card, driving license, or passport through a number of systems. The biggest of these will likely be AgeID, a project run by MindGeek, the owner of the world’s biggest porn sites including Pornhub and YouPorn. Alternatively, individuals can buy porn passes for £4.99 ($6.60) from local shops, which will verify the customer’s age in person as they would for the purchase of alcohol.

Porn sites that don’t introduce age checks will be blocked by ISPs, but the legislation doesn’t cover social media sites like Reddit and Twitter, which host adult content. Internet users in the UK will also be able to navigate the block using virtual private networks or VPNs — services that redirect internet traffic through different parts of the world.

“The policy is completely full of holes,” Jim Killock, executive director of the UK’s Open Rights Group, told The Verge last year. “It puts too much power in the hands of companies, [and] if teenagers in particular have any incentive to get around these controls, they will.”