4chan Challenges Ofcom’s Jurisdiction under the UK’s Online Safety Act

The US-based image board site 4chan has publicly refused to pay a £20,000 fine provisionally issued by Ofcom for alleged non-compliance with the UK’s Online Safety Act 2023 (“OSA”). In response, 4chan has subsequently launched a legal challenge against Ofcom in a Washington DC federal court seeking to ban Ofcom from enforcing or attempting to enforce the OSA against them in the US.

This development raises important questions regarding the practical enforceability of a UK digital regulation in a globally distributed online environment, particularly in relation to platforms with no physical presence in the UK.

Background

The 4chan platform has long been seen as one of the more controversial sites available on the internet as it allows its users to post anonymously. This anonymity has led to the proliferation of harmful and extreme material on 4chan such as hate speech and misogynistic campaigns.

The UK’s telecommunications regulator, Ofcom launched an investigation into 4chan in June 2025 after it was reported that the site failed to comply with statutory information requests under the OSA. The regulator contends that the site failed to submit an illegal content risk assessment, record-keeping requirements, and appropriate safety measures to protect its users from illegal content. 

In August 2025, Ofcom issued 4chan a 'provisional notice of contravention' for 4chan's alleged failures to comply with two statutory information requests. As a result, Ofcom has provisionally decided to issue a £20,000 fine as well as daily penalties until 4chan complies with the information requests.

Under the OSA, it is compulsory for online platforms like 4chan to have systems in place that can detect and take down illegal and harmful content to protect UK users. The OSA has extra-territorial effect and applies to service providers that:

• provide services to a significant number of users in the UK;
• target the UK market; or
• (in case of U2U services and search services) are capable of being used in the UK by individuals and there are reasonable grounds to believe that there is a material risk of significant harm to individuals in the UK presented by the user-generated content or search content on that service.

Jurisdictional dispute

The legal complaint, filed on behalf of 4Chan, argues that Ofcom’s enforcement efforts violate US constitutional protections, including free speech rights under the First Amendment. 4chan seeks a permanent injunction prohibiting Ofcom from enforcing the OSA in the US and a declaration that its demands are unenforceable under US law.

Lawyers for 4chan contend that Ofcom’s actions amount to an “illegal campaign of harassment” against US businesses with no UK establishment (4chan is incorporated in Delaware with no UK establishment). Ofcom maintains that services with UK users or targeting the UK market are subject to the OSA, regardless of where they are based.

This dispute emerges against a backdrop of increasing resistance from the US government to foreign regulatory mandates perceived as extraterritorial. The current US administration has voiced concerns over international efforts that may restrict US companies’ operations or free speech rights. Notably, the Federal Trade Commission has similarly cautioned against compliance with foreign censorship requirements, explicitly referencing the OSA as a potential threat to US constitutional principles.

Enforcement options for Ofcom

Even if 4chan successfully resists the fine in the US and the platform chooses to remain non-compliant, Ofcom may consider alternative enforcement mechanisms. These include seeking court orders to block access via UK internet service providers, removing the site from search results, and restricting its payment processing capabilities. Such measures reflect a growing trend among regulators to pursue operational remedies where direct financial enforcement is not feasible.

Comment

This dispute demonstrates the challenge of enforcing the UK online safety obligations against offshore platforms and underscores the tension of national regulatory frameworks and global digital governance. 

The outcome of this dispute may set a precedent for the enforceability of the UK’s online safety obligations against US-based, and potentially other non-UK based, platforms and will be closely watched by stakeholders across the digital, legal and policy landscape.

For online service providers operating across jurisdictions, this serves as a timely reminder of the need to assess cross-border compliance risks and develop robust strategies for cross-border compliance.

If you would like any further information or have any questions about the contents of this article, please contact  Richard Hugo, Amanda Leiu or another member of our Commercial & Technology team. 

This article was written by Mopé Akinyemi and Amanda Leiu.