Online videos and social media posts with fake and misleading information about the coronavirus pandemic are often watched by hundreds of thousands of people around the world.
We've been fact-checking some of those most widely shared this week.
"Fake" death figures?
First up, a video featuring the right-wing conspiracy theorist Alex Jones calling America's coronavirus data "fake". It's being used, he suggests, to keep the country in lockdown and to scupper President Trump's bid for re-election.
He argues that the Covid-19 death figures are wrong, but in doing so he misinterprets how the information is recorded.
Mr Jones says anyone who tests positive for Covid-19 at the time of their death - be it due to "cancer", "sky-diving accidents" or "shark attacks" - is being recorded as a death due to coronavirus.
Covid-19 is only listed on the death certificate in the United States if the disease played a role in that person dying, so deaths by misadventure such as shark attacks and sky-diving falls would certainly not be included.
Experts say that, if anything, Covid-19 deaths have been under-reported, because of a lack of testing in the community, and deaths at home which aren't counted.
Calculating death rates is certainly not an exact science and is open to interpretation. We've written extensively about how these figures are worked out in the UK:
Mr Jones also claims that anyone who has ever had any coronavirus infection, or the common cold, will produce a positive test.
The tests currently being widely used across the US and elsewhere are to find out whether you are infected with the novel coronavirus responsible for the pandemic.
"The diagnostic tests for Covid-19 are specific for the SARS-CoV-2 virus (which causes it)," says Dr Jeremy Rossman, Honorary Senior Lecturer in Virology at the University of Kent. "They do not detect other coronaviruses nor do they detect the common cold virus (rhinovirus) or the flu virus."
These tests do not identify previous infections from which you have recovered - although scientists are working hard to roll out a reliable test for this too.
The video has been shared many thousands of times but was not posted on Alex Jones' main account or his Infowars Facebook page, because both of them have been banned by Facebook.
The sad story behind a body bag video
A viral video claiming an elderly woman with coronavirus was put in a body bag while still alive has been exposed as misleading.
The video originated in Brazil and went viral on WhatsApp and Facebook. Various versions have been shared hundreds of thousands of times, including in large English-language conspiracy groups.
The video shows an elderly patient on top of plastic sheeting struggling to breathe. The caption claims the woman's family was told she was dead.
The truth is less dramatic. The director of the Abelardo Santos Hospital in northern Brazil told BBC News Brasil that the protective sheeting she is lying on is indeed a body bag, but it was used to transfer her to another bed.
"It's a common practice in hospitals," he said, "especially during a pandemic or an epidemic, which force us to adapt".
The police are looking into who leaked the video and who is responsible for the spread of fake news related to it.
Since the footage was recorded, the woman has sadly died.
Some of the posts in Portuguese on Facebook feature a warning message that they are misleading. However, we've spotted some in English which have not been flagged by Facebook.
No, this scientist did not say US and China created coronavirus
A fake quote attributed to a prominent French scientist went viral this week.
The Facebook post claims Professor Didier Raoult (a specialist in infectious diseases) said Covid-19 was created by the United States and China to kill millions of Africans.
We spoke to the hospital in Marseille where Prof Raoult works and they confirmed it's not genuine.
Prof Raoult has become well-known for promoting an anti-Malarial drug to treat coronavirus.
The original post, which can be traced back to an account in the Democratic Republic of Congo, has been shared more than 150,000 times in a number of African countries, including Madagascar and Cameroon.
And there's an intriguing twist to this story. Another fake story we reported on linked to the same Instagram account.
Anger at how African countries are being treated during the pandemic has repeatedly surfaced online. Two French doctors have been accused of racism after suggesting vaccine trials in Africa.
Forced quarantine is not coming to America
Lastly, we've taken a look at a video which contains false information about powers being introduced in the United States to forcibly remove infected individuals from their home and into quarantine.
In the video, Dr Rashid Buttar, know for holding anti-vaccination views, says a new bill being introduced in the US Congress will give authorities these powers.
However, this is false - the bill does no such thing. It is a request for funds to help contain the spread of the virus and boost testing, particularly in areas with poorer health services.
As part of this process, some of the funds would be used for contact tracing, which means tracking people down who might have come into contact with someone with coronavirus.
Dr Buttar suggests that under the bill authorities would be allowed into your house if you show coronavirus symptoms. This clip has had more than three million views on Facebook.
The bill does mention that where necessary people could be tested in their homes, but makes it clear that existing federal privacy or confidentiality laws would not be superseded.
Despite various claims by Dr Buttar about relatives being taken away, there is nothing in the proposal about people being removed from their homes.
Additional reporting by Marianna Spring, Olga Robinson and BBC News Brasil.