Facebook and Twitter could be asked to pay a tax to help fund educational campaigns about internet abuse.
It is among ideas suggested by the UK government as it considers its safer internet strategy.
It also proposed that social media platforms reveal the true scale of online hate and how much content is removed each year.
And it wants a code of practice to ensure providers offer adequate online safety.
under-age access to pornography
The UK's Culture Secretary, Karen Bradley, said social-media companies had to face up to their responsibilities.
"The internet has been an amazing force for good, but it has caused undeniable suffering and can be an especially harmful place for children and vulnerable people," she said.
"Behavior that is unacceptable in real life is unacceptable on a computer screen, and we need an approach to the internet that protects everyone without restricting growth and innovation in the digital economy.
"Our ideas are ambitious - and rightly so. Collaboratively, government, industry, parents and communities can keep citizens safe online, but only by working together."
According to the government, almost a fifth of 12- to 15-year-olds have seen something they found worrying or nasty, and almost half of adults have seen something that has upset or offended them, on social media.
One of the proposals is for an annual transparency report which could be used to show:
the volume of content reported to companies and the proportion taken down
how users' complaints are handled
categories of complaints, including from under-18s, women, the LGBT community or on religious grounds
information about how each site moderates content
Ms Bradley said that the government "could legislate in the future", adding that any changes to existing law would be underpinned by the following principles:
What is unacceptable offline, should be unacceptable online
All users should be empowered to manage online risks and stay safe
Technology companies have a responsibility to their users
It also wants to see a new body, similar to the UK Council for Child Internet Safety, to consider all aspects of internet safety.
In response to the consultation, Facebook said: "Our priority is to make Facebook a safe place for people of all ages which is why we spent a long time working with safety experts like the UK Safer Internet Centre, developing powerful tools to help people have a positive experience.We welcome close collaboration between industry, experts and government to address this important issue."
Vicki Shotbolt, chief executive at social enterprise Parent Zone, said it was encouraging to see the government taking "concrete steps" to make the internet a safer place for children.
社会企业Parent Zone的首席执行官Vicki Shotbolt称，看到政府采取“具体措施”提高儿童的网上安全，此举令人振奋。
A spokesperson for the NSPCC said keeping young people safe online was "the biggest child protection issue of our time".
"Social media companies are marking their own homework when it comes to keeping children safe, so a code of practice is definitely a step in the right direction but 'how' it is implemented will be crucial.
"Young people face a unique set of risks when using the internet and it is important any strategy recognizes the challenges they face online and requires industry to act to protect them."
Asking social-media companies to contribute towards the costs of educating the public about online dangers has precedence in the gambling industry, which currently contributes an amount to the treatment of gambling addiction.