The "biggest, richest and cleverest" companies in the world may face prosecution in the UK for leaving unlawful messages on their sites if MPs have their way.
The Commons Home Affairs Select Committee has urged the next government to consider urgently a change in the law so that social media operators can be prosecuted for leaving unlawful messages on their sites.
It is also asking that web companies be charged a fee for police investigations into illegal online posts, much as football teams are charged for match-day policing, the Times reports.
Yvette Cooper, chair of the committee, said: "These are among the biggest, richest, and cleverest companies in the world and their services have become a crucial part of people's lives.
"Social media companies' failure to deal with illegal and dangerous material online is a disgrace. It is shameful.
"They continue to operate as platforms for hatred and extremism without even taking basic steps to make sure they can quickly stop illegal material, properly enforce their own standards or keep people safe."
The MPs held an inquiry into hate crime and its consequences after Jo Cox, a Labour MP, was killed by far-right terrorist Thomas Mair who searched online for material on Nazism and white supremacism.
Amber Rudd, the home secretary has promised to study the committee's recommendations and said she expected the social media companies to take "early and effective action," BBC reports.
Twitter: 'Vile and provocative images'
The inquiry found that it was "shockingly easy" to access material on Google, Twitter and Facebook targeted at stirring up racial hatred.
The MPs reported the postings to the internet companies but they remained accessible even after the complaints. While Twitter removed some tweets and suspended most of the offending accounts, many of the same "vile and provocative images could still be found on the platform six weeks later", said the committee.
Facebook: The 'vehicle of choice for terrorist propaganda'
The lawmakers highlighted how Twitter refused to take down a cartoon of a group of male, ethnic minority migrants tying up and abusing a semi-naked white woman while stabbing her baby on the grounds that "it was not in breach of [Twitter's] hateful content policy".
"Given their immense size, resources and global reach, it is completely irresponsible of them to fail to abide by the law, and to keep their users and others safe," the report says.
It noted that YouTube was the "vehicle of choice" for terrorist propaganda and attracting recruits while Twitter had been a "magnet for jihadist propaganda."
The report said that hatred, abuse and extremism were growing at an alarming rate but remained unchecked and, even when illegal, largely unpoliced by the operators.
Google 'profited from hatred'
The MPs slammed Google for acting quickly to remove videos from YouTube when "they are found to infringe copyright rules but that the same prompt action is not taken when the material involves hateful or illegal content".
"The most salient fact is that one of the world's largest companies has profited from hatred and allowed itself to be a platform from which extremists have generated revenue."
Social media companies respond
Twitter told the MPs that the company was becoming more proactive and was using technology better and collaborating with counter-terrorist and child protection experts.
Simon Milner, the director of policy at Facebook, said: "Nothing is more important to us than people's safety on Facebook. That is why we have quick and easy ways for people to report content, so that we can review and if necessary remove it from our platform."
YouTube had this to say: "We take this issue very seriously. We've recently tightened our advertising policies and enforcement, made algorithmic updates, and are expanding our partnerships with specialist organisations working in this field."