The final draft of the UK government’s long-awaited legislation designed to protect people from “harmful” content on the internet is today being presented to Parliament.

The Online Safety Bill is wide-ranging. Technology companies such as Twitter, Google, Facebook and TikTok get a host of new responsibilities. They have to check all adverts appearing on their platforms to make sure they aren’t frauds, while those that allow adult content will have to verify the age of users to ensure they aren’t children.

Online platforms will also have to proactively remove anything that is deemed “harmful content”—details of what this includes remain unclear, but the announcement today mentioned the examples “self-harm, harassment and eating disorders”.

The bill also gives stronger powers to regulators and watchdogs to investigate breaches: a new criminal offence will be introduced to prevent employees of firms covered by the legislation from tampering with data before handing it over, and another for stopping or obstructing raids or investigations. The regulator Office of Communication (Ofcom) will have the power to fine companies up to 10 per cent of their annual global turnover.

Alan Woodward at the University of Surrey in the UK says the legislation is being proposed with good intentions, but the devil is in the detail. “The first issue comes about when trying to define ’harm’,” he says. “Differentiating between harmful and free speech is filled with difficulty. Some subjective test doesn’t really give the sort of certainty technology companies will need if they face being held liable for enabling such content.”

He also points out that tech-sawy children will be able to use VPNs, the Tor browser and other tricks to easily get around the measures relating to age verification and user identity.

There are also concerns that the bill will cause technology companies to take a cautious approach to what they allow on their sites that ends up suppressing free speech, open discussion and potentially useful content with controversial themes.

Anything that increases the burden of responsibility and introduces new risks for negligence won’t be popular with tech firms, and companies that operate globally are unlikely to be pleased at the prospect of having to create new tools and procedures for the UK market alone.

Google and Facebook didn’t respond to a request for comment, while Twitter’s Katy Minshall says “a one-size-fits-all approach fails to consider the diversity of our online environment”. But she added that Twitter would “look forward to reviewing” the bill.

It can be learned from the last two paragraphs that the bill________.