The internet has added a new dimension to the spaces of imagination in which we all live, and the problems of the offline world have moved there, too. This did not once seem an urgent problem, but in the last five years there has been a revolution of attitude around the world away from the anarchic culture encouraged by US law; at the other extreme is the very tight censorship imposed in China, where one popular startup employs as many people on content moderation as it does selling advertising.

The white paper announced by the government on Monday attempts to steer a middle course, as most of the world does. There is to be real regulation, with painful fines, for almost all of the public internet. Persistent offenders against codes of conduct as yet unspecified will, so far as possible, be rendered inaccessible to British web users. The platforms are no longer to be regarded as entirely neutral conduits, with no more responsibility for the content they spread – and in most cases sell advertising against – than the telephone company has for the content of telephone conversations.

This is a welcome step towards a sane regulation of the internet. But it is important not to go too far. The proposals in the white paper, although they look mostly sensible at first glance, are in some cases too ambitious, and in others unrealistically feeble. This reflects in part the conflicting political pressures under which it has been generated. It is the product of two government departments – the Department for Digital, Culture, Media and Sport, and the Home Office – and it reads like that.

No one doubts the harm done by child sexual abuse or terrorist propaganda online, but these things are already illegal. The difficulty there is enforcement, which the white paper does nothing to address. Effective enforcement would demand a great deal of money and human time, which neither the government nor the tech companies wish to spend. The present system relies on a mixture of human reporting and algorithms. The algorithms can be fooled without too much trouble: 300,000 of the 1.5m copies of the Christchurch terrorist videos that were uploaded to Facebook within 24 hours of the crime were undetected by automated systems. Meanwhile, detection of the great majority of truly offensive material relies on it being reported by human beings. The problem there is incentives: the people most likely to see such things will have sought them out deliberately, and so they have no reason to report them.

Beyond that, there is a conceptual problem. Much of the harm done on and by social media does not come from deliberate criminality, but from ordinary people released from the constraints of civility. It is here that the white paper fails most seriously. It talks about material – such as “intimidation, disinformation, the advocacy of self-harm” – that is harmful but not illegal yet proposes to regulate it in the same way as material which is both. Even leaving aside politically motivated disinformation, this is an area where much deeper and clearer thought is needed.

There is no doubt that some forms of disinformation, such as anti-vaccination propaganda, do serious harms both to individuals and to society as a whole. But does the government really want fines levied on the executives of YouTube when the platform promotes conspiracy theories or anti-vaxx videos? Regulating the internet is necessary, but it won’t be easy or cheap. Too much of this white paper looks like an attempt to find cheap and easy solutions to really hard questions.