Facebook and Twitter could face 'online abuse' tax
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.
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.