You've probably seen it by now: the 27-second video of alt-right white nationalist Richard Spencer being punched as he described his Pepe lapel pin at a protest against Donald Trump's inauguration over the weekend.
The footage has been ripped and viewed hundreds of thousands of times. It's been memed and set to every single song under the sun. It's also kicked off several days of online debate about whether it's OK to punch a "Nazi".
Richard Spencer is an attention-seeking white supremacist who was caught on camera at a conference in November last year leading a crowd in salutes reminiscent of the Nazis.
The video even prompted the New York Times to pose the question to its readers.
BuzzFeed News spoke to veteran Australian journalist Zoe Daniel, who was on the other side of the camera when Spencer was punched.
Daniel, who was covering the Washington protests for Australia's public broadcaster the ABC, said there was rising tension in the area as police started tear-gassing protesters and firing flashbangs.
The impromptu TV interview started after Daniel had noticed Spencer off-camera being punched by a protester.
"We were talking to a woman who had been teargassed on the corner of K Street, when I saw Richard Spencer standing there... and he got hit," Daniel said. "I went to ask what his reaction was to being hit by a random stranger on the street, but also to ask him what he was doing there at the protests because that particular area was quite heated.
"As I was talking to him, the masked man came in again a lot harder and king-hit him in the head, which is what is in the footage."
Daniel said she went to check whether he was OK: "He sort of came back and continued to talk to us, but I said, 'I don’t think this is a good place for you to be; maybe you should go?'"
Daniel's been a little surprised by the online fallout, especially the "amount of memes and various videos to music". But she said it's also triggered a wider debate about violence in the era of Trump.
"I guess it has provoked a bigger debate about what is OK because people are obviously trying to justify the fact he was hit on the basis of the sort of person he is and the beliefs he holds."
The journalist, who has also been a foreign correspondent in Southeast Asia and Africa, likened the punch to those seen in street assaults in Australia, which have left young men dead.
"My fairly clear-cut view is that king-hitting someone from behind, or from the side, in what is effectively a 'coward punch' is not a good approach," she said. "We’ve seen many times in Australia young men be killed from this type of punch."
Both "king hit" and "coward punch" are Australian terms for punches laid on people while they're not looking. Other places would know it simply as a "sucker punch".
As to the question of whether Spencer should be interviewed in the first place, Daniel said: "People have questioned... 'Why would you air the views of this person who has a very toxic perspective on many things?'
"Our job as communicators is to converse with people and try to understand their perspective on things, which is why you have those conversations with people who have all sorts of different viewpoints."