Facebook chief executive Mark Zuckerberg. Drew Angerer/Getty Images

LONDON — Facebook, Google, and other tech companies might have to pay a levy to counteract online bullies and trolls, according to new proposals put forward by the UK government.

Culture secretary Karen Bradley has proposed an "industry-wide levy" on social media firms, internet providers, and mobile firms to "raise awareness and counter internet harms."

The idea is to force tech firms to deal with the consequences of online bullying, trolling, and unfettered access to porn.

The government hasn't gone into any further detail, and has not specified how much it might levy tech firms, how it would collect the cash, or what exactly the cash would be used for.

It has hinted at full regulation of the internet before. The Conservative election manifesto this year said: "Some people say that it is not for government to regulate when it comes to technology and the internet. We disagree."

And a BuzzFeed investigation uncovered plans for an internet levy at the time.

Actually forcing tech firms to pay up might be tricky. It's possible the government would calculate the levy amount based on each company's taxable revenue, but that poses difficulties.

Jim Killock, director of privacy campaigning group Open Rights Watch, said: "This could be hard to implement in a way that is fair. Many smaller social media companies may have no UK presence for instance. Others may have no taxable revenue.

"Ultimately, it is individuals who break the law. Often governments seem to want policing to be done by companies, but we should remember that Facebook and Google do not run courts of law, and they do not put people in prison. The government needs to be clear that the police will pursue wrongdoers when laws are broken."

Google and Facebook did not respond to requests for comment.

A spokesman for Twitter pointed to the increased work the company was doing to keep people safe on its platform, though the firm is often criticised for a culture of trolling and abuse. Twitter said it was blocked ten times the number of abusive accounts every day compared to last year, and said it had retrained its support team to recognise "hateful conduct."

A Microsoft spokeswoman said: "Microsoft is committed to help all those who use our technology to get online, do so in safety. Keeping people safe online is a problem that cannot be solved with each of us acting alone. This is why we are a founding member of the Internet Watch Foundation, and make information and tools available on our platforms. We welcome the Government’s Internet Safety Strategy, and the consultation process to find new ways to protect people from harm."

It's also possible the government will never enforce a levy at all. The proposal is part of Karen Bradley's green paper on internet safety — a consultation document that will be open to wider debate before the government considers enshrining any suggestions in policy.