The man who pointed out that everyone compares everything to Nazis says it's OK to call alt-right protestors Nazis.

Mike Godwin formulated Godwin's Law more than 25 years ago. And it has become a foundational rule of the internet in the time since: as a discussion goes on, the likelihood of someone being called a Nazi becomes higher.

Some have added an extra part: as soon as someone is called a Nazi, they are probably wrong.

But Mr Godwin has said that the white nationalists who took over the streets of Charlottesville over the weekend can fairly be compared to Nazis, given that many of them openly voice support for a Nazi ideology.

"By all means, compare these s***heads to the Nazis," he wrote. "Again and again. I'm with you."

Violence on the streets of Charlottesville Show all 9 1 /9 Violence on the streets of Charlottesville Violence on the streets of Charlottesville Protesters clash and several are injured White nationalist demonstrators clash with counter demonstrators at the entrance to Lee Park in Charlottesville, Virginia. A state of emergency is declared, August 12 2017 Violence on the streets of Charlottesville Trump supporters at the protest A white nationalist demonstrator walks into Lee Park in Charlottesville, Va., Saturday, Aug. 12, 2017. Hundreds of people chanted, threw punches, hurled water bottles and unleashed chemical sprays on each other Saturday after violence erupted at a white nationalist rally in Virginia. AP Photo Violence on the streets of Charlottesville State police stand ready in riot gear Virginia State Police cordon off an area around the site where a car ran into a group of protesters after a white nationalist rally in Charlottesville, Virginia AP Photo Violence on the streets of Charlottesville Militia armed with assault rifles White nationalists, neo-Nazis and members of the 'alt-right' with body armor and combat weapons evacuate comrades who were pepper sprayed after the 'Unite the Right' rally was declared a unlawful gathering by Virginia State Police. Militia members marched through the city earlier in the day, armed with assault rifles. Getty Images Violence on the streets of Charlottesville Statue of Confederate General Robert E Lee The statue of Confederate General Robert E. Lee stands behind a crowd of hundreds of white nationalists, neo-Nazis and members of the 'alt-right' during the 'Unite the Right' rally 12 August 2017 in Charlottesville, Virginia. They are protesting the removal of the statue from Emancipation Park in the city. Getty Images Violence on the streets of Charlottesville Racial tensions sparked the violence White nationalists, neo-Nazis and members of the 'alt-right' exchange insults with counter-protesters as they attempt to guard the entrance to Lee Park during the 'Unite the Right' rally Getty Violence on the streets of Charlottesville A car plows through protesters A vehicle drives into a group of protesters demonstrating against a white nationalist rally in Charlottesville, Virginia. The incident resulted in multiple injuries, some life-threatening, and one death. AP Photo Violence on the streets of Charlottesville Rescue personnel help injured people after a car ran into a large group of protesters after an white nationalist rally in Charlottesville, Virginia AP Photo Violence on the streets of Charlottesville President Donald Trump speaks about the ongoing situation in Charlottesville, Virginia from his golf club in Bedminster, New Jersey. He spoke about "loyalty" and "healing wounds" left by decades of racism.

Mr Godwin has said before that he is fine with Nazi comparisons, so long as they are thought-out and historically informed. At the Charlottesville rally, protestors carried Swastika flags and made Nazi salutes.

"If you’re thoughtful about it and show some real awareness of history, go ahead and refer to Hitler or Nazis when you talk about Trump," he wrote in the Washington Post late last year. "Or any other politician."

He went on to make clear that he thinks that references to the Holocaust and other Nazi crimes are legitimate and can be helpful, in some cases.

"To be clear: I don’t personally believe all rational discourse has ended when Nazis or the Holocaust are invoked," he wrote. "But I’m pleased that people still use Godwin’s Law to force one another to argue more thoughtfully.

"The best way to prevent future holocausts, I believe, is not to forbear from Holocaust comparisons; instead, it’s to make sure that those comparisons are meaningful and substantive."

The original formulation of Godwin's Law goes: "As an online discussion grows longer, the probability of a comparison involving Nazis or Hitler approaches one". That is, any discussion online is likely to turn into Nazi comparisons, at some point.

Its clear truth has led it to become famous on the internet. And it has been used as a kind of fallacy, where people argue that anyone who invokes Hitler or the Nazis has inevitably lost an argument, though Mr Godwin has made clear that isn't always the case.

Charlottesville mayor: There's a 'direct line' between what happened here and Trump

In follow-up message on Facebook, Mr Godwin made clear that he had made the statement in response to a request.

"This is in response to a direct-message request: 'Mr. Godwin, pardon the lack of proper introduction, but I believe you to be the man who created the Internet adage now known as "Godwin's Law"," he said. "Sir, I implore you to post a statement on FB, giving your views on the recent white nationalist rally in Charlottesville Virginia.