From the idea that the coronavirus was created in a lab to the belief that it is all part of a plan to bring in compulsory vaccinations, conspiracy theories have been plentiful in recent months.
Now, research indicates that people who get their news from social media are more likely to believe in such theories - and also more likely to break lockdown rules.
Researchers from King's College London and Ipsos Mori found that some conspiracy theories were believed by quite a high proportion of the population.
In an online survey of over 2,000 people carried out in late May, 30% thought that the coronavirus was created in a lab, up from 25% in April. A similar proportion thought the true death toll from Covid-19 was being hidden by the authorities.
About 13% believed the pandemic was part of a global effort to force everyone to be vaccinated, and 8% believed there was some connection between symptoms and radiation from 5G phone masts.
In an article in the journal Psychological Medicine, the researchers from King's College described how people who believed in conspiracy theories tended to be more dependent on social media for information and were less likely to follow official health advice.
Some 60% of those who believe that Covid-19 symptoms were linked to 5G radiation said that much of their information on the virus came from YouTube - while of those who believed that was false, just 14% said they depended on the site.
People who had ignored official advice and gone outside despite having symptoms of the virus were also far more likely to have relied on YouTube for information.
"This is not surprising, given that so much of the information on social media is misleading or downright wrong," said Dr Daniel Allington.
He said access to good quality information was getting even more important as lockdown rules were eased and people had to make their own decisions about what was safe or unsafe.
The survey suggested that TV and radio programmes are the main way most people get information about the virus, followed by newspapers and magazines.
But 45% of 16-to-24 year olds said they got much of their information from YouTube, while nearly 40% of the under-35s said Facebook was a major source for them.
Political allegiances also played a part in whether people believe in conspiracy theories: 39% of Conservative voters thought coronavirus was probably created in a lab, compared with 23% of Labour voters.
But Labour voters were twice as likely as Conservatives to think the death toll was being deliberately concealed by the authorities.
Facebook, YouTube and Twitter have all outlined policies to try to combat misinformation about the virus.
Some of the more extreme conspiracy theorists have found themselves banned from a number of the platforms, but search for "5G coronavirus" on any of the big social media sites and you will still find a wealth of conspiratorial material.
This report suggests that this tide of rumour and misinformation continues to provide a challenge for a government trying to persuade people to limit risky behaviour and control the spread of the virus.