A British charity might be the catalyst for a drastic change in the way the U.K.’s Internet works—by making porn available only for users who “opt into” seeing explicit sites.

In an editorial in the U.K.’s Daily Mail, Esther Rantzen, president of a free counseling service for children called ChildLine, wrote that the British government “is on the cusp” of needing to make a decision on whether to adopt the system.

“I prize freedom of speech, and loathe censorship,” Rantzen wrote. “Nonetheless, I am absolutely convinced […] to protect our children against the filthy tide of pornography on the Internet that threatens to engulf them.”

The system is simple in concept, though it would be difficult to implement in practice. A government agency would provide Internet service providers with a list of websites to block until a customer explicitly asks to have that block removed. In short, users would “opt-in” to seeing explicit sites.

It’s not as far-fetched as it might seem. Prime Minister David Cameron has expressed support for such a system and has commissioned a massive report on the subject. One portion of the report, which crowdsourced for opinions, was a privacy disaster; anyone could see even “confidential” forms that included people’s email addresses, full names, and opinions on Internet porn. Still, 37 percent of Britons support the opt-in system.

Privacy advocates, unsurprisingly, oppose the idea. As British privacy advocate Big Brother Watch noted, “Ultimately the risk is that ISPs will be expected to monitor everything their customers do online to ensure they are not doing something they should not be.”

Besides, as the group noted, the Netherlands abandoned a similar system in 2011 after concluding it didn’t work.

Photo via Esther Rantzen/Facebook