The problem is he's a racist crank with no expertise in viruses and a long history of writing nonsense.
His recent output on ResearchGate (which he was repeatedly warned about before the ban) includes articles claiming "vaccines are inherently dangerous" and that the surge in deaths last spring wasn't caused by covid but was "mass homicide by government response".
Before covid he was also a climate change denier.
A 2007 article claimed global warming was a "useful myth" that "deflects attention away from real world issues" such as "power-driven financiers, corporations and their cartels backed by military might".
This seems to be a common thread. As a physics professor in 2005 he turned an environmental studies class into a workshop on "what the high priests of science have been talking about and how science is being used". Without telling university officials.
One series of posts, in which he accused a law professor of acting like the university president's "house negro" and trying to discredit reports of systemic racism, later resulted in him being sued for libel.
He walked out of the trial (in which he was representing himself) after accusing the judge of being biased and running a "kangaroo court", and compared it to a Stalinist show trial.
When he was eventually fired by the university in 2009, accused of inflating grades after giving all 23 students on one course an A+, he blamed "the military industrial complex and the Israel lobby" for his misfortune.
This seems to have escalated into a full-on antisemitic rant, in which he apparently accused the "Israel lobby" of being "chief-whip for the US military economic finance empire" and providing "direct and forceful control of politicians and intellectuals".
A racist conspiracy theorist who believes Israel and its supporters in the US are secretly running the world, supported by the mainstream media and pop culture.
Maybe, as with Michael Yeadon's Islamaphobia, covid sceptics will turn a blind eye to Rancourt's antisemitism. Because he supports their beliefs on masks, lockdowns and vaccines (despite a lack of expertise in the field).
But don't let them forget they associate with racists.
In case anyone thinks this was an isolated incident, here he is again in 2014, tweeting about a blog post he wrote which says the Israel lobby "serves to align and discipline all the politicians" and uses the holocaust to "levy compliance".
His covid writings are equally crazy. Here he is way back in March 2020, suggesting covid-19 might be a biological weapon designed to kill Iranians, seeded in China by US soldiers, and that "media hysteria" about the virus was coordinated by the CIA.
We now have data from mass testing in schools for the first 4 weeks after they fully reopened on March 8th, up to the end of the spring term.
The results suggest that transmission of the virus *has* increased since schools went back .. but mostly amongst staff.
Starting with nurseries and primary schools, the data initially looks rather alarming, with a huge jump in positivity rates the week after schools reopened.
However...
The data is also broken down by role within the school, and we can see that the government started rolling out free lateral flow tests for support and household bubbles to use at home when schools fully reopened.
These are included in the main school test figures!
He says it's "hard to imagine, let alone measure, the side effects of lockdowns", and kind of proves that by listing lots of deaths that mostly have nothing to do with lockdown.
The latest graph and interview from @RealJoelSmalley starts by claiming that the response to covid killed more people than covid itself, and ends with a wild theory that vaccination drove the surge in deaths in January!
Needless to say, there's no real evidence to support this.
First he claims that there have been almost 40,000 deaths over the last year due to denial of healthcare.
Many of them over the summer, when there were no excess deaths!
As he says in his podcast interview, "any analysis is worthless if the data that goes in is not good".
And his data is not good.
Instead of using the five year average, he generates a baseline curve that he believes deaths would have followed in 2020 without covid and lockdown.
But this is based purely on deaths in late January / early February, extended out to the whole year!
There are anti-immigrant posts citing Enoch Powell's "rivers of blood" speech and calling an old French novel about immigrants taking over the west "a good approximation of reality".
Sceptics make wild claims about the number of deaths caused by lockdown, but there's no evidence to support them.
The vast majority of excess deaths last year were directly caused by ("from", not "with") covid-19.
So what do ONS and PHE data and academic studies actually show?
Removing covid deaths, you can see more clearly that despite 10 months of varying levels of restrictions, the only time there have been large numbers of non-covid excess deaths was during the first wave.
Mostly elderly care home residents registered as dying from dementia.
We now know that many elderly people suffering from covid experience confusion and delirium, often without a cough or fever.
This is obviously easily mistaken for other, pre-existing conditions.
The same thing is thought to happen with flu each winter.
The latest Test & Trace report is out, covering the week before Christmas.
Cases in London and the South East were soaring, and an outbreak of coronavirus at the Lighthouse Lab in Milton Keynes caused further issues in the testing system as demand for tests rapidly increased.
There was another big increase in testing as demand rose, with increasing numbers of quick but less sensitive Lateral Flow Tests being used to screen asymptomatic people.
In total 2.6 million tests were done. But a higher percentage than last week were positive.
If you separate Lateral Flow (which are ONLY used on asymptomatic people) and PCR (which are used on both symptomatic and asymptomatic people) tests, positivity for PCR is back to the peak last seen at the beginning of November, while positivity for LFTs is rising fast now too.