An overwhelming majority of the public believe social media companies do not do enough to tackle bullying, illegal activities and the spreading of extremist content on their sites, a major survey has found.
Most people think companies like Facebook and Twitter are not regulated enough (64%) and lack transparency (63%), according to the Edelman Trust Barometer.
Just over half (57%) believe social media firms take advantage of users' loneliness and 62% think they are selling people's data without their knowledge (62%).
It showed seven in 10 people believe social media companies do not do enough to stop illegal or unethical behaviour on their platforms, prevent the sharing of extremist content or do enough to prevent bullying.
Around one third (34%) do not think social media is a force for good in society.
Facebook, Twitter and other online giants have faced intense criticism from MPs over the way they deal with offensive or extreme content and the Government has warned they face penalties if they refuse to tighten up controls.
Ed Williams, chief executive officer of Edelman UK, said: "After a flood of negative headlines in 2017, it's time these companies sat up and listened.
"The public want action on key issues related to online protection, and to see their concerns addressed through better regulation. Failure on their part to act risks further erosion of trust and therefore public support."
The wide-ranging study also found trust in government remains languishing at just 36%, the same as 2017, and 40% believe it abuses its power more than any other pillar of society.
But trust in party leaders Theresa May and Jeremy Corbyn has risen over the last 12 months.
The Prime Minister enjoyed a four-point bounce, 35% to 39%, while the Labour leader scored an extra 13 points, 23% to 36%.
According to the research, 39% of the public back Brexit while 43% are opposed and 12% said they did not care either way.
Distrust in business is fuelled mainly by concerns over high executive pay (58%), tax avoidance (56%) and a lack of transparency in business dealings (45%).
Charles Bowman, Lord Mayor of the City of London, and a spokesman for the UK's financial and professional services sector, said: "With trust in business remaining low, today's findings show that business has a lot still to do.
"Improving trust in business is the focus of my mayoral year through the Business of Trust programme."
- More than 33,000 respondents took part in 30-minute online interviews from October 28 to November 20 2017.
The survey included 6,200 "informed public respondents" who were aged 25-64, college-educated; a household income in the top quartile for their age in their country; read or watch business/news media at least several times a week; follow public policy issues in the news at least several times a week.