A number of users jumped on the hashtag to express their disappointment over the "racist" move, but others were dismayed by the internet's unhealthy obsession with cancelling celebrities in isolation.
The clip was uploaded with the caption "NBC fired Megyn Kelly for mentioning blackface. Jimmy Fallon performed on NBC in blackface", in reference to the US Morning Show anchor claiming that blackface was acceptable in the context of Halloween costumes in 2018.
Kelly had said blackface was "okay when I was a kid as long as you were dressing like a character".
The backlash was swift, and although she apologised during her next appearance, she was dropped from the show shortly after.
Many expressed confusion over the fresh wave of criticism, given the clip is 20 years old and has been circulated and debated many times before. Others pointed out that a number of comedians have performed in blackface on SNL and should be copping the same criticism.
Fallon has actually performed his Chris Rock impersonation a second time since 2000, at the 2017 Golden Globes (sans face paint).
The TV personality rolled out a drunken impression of Chris Rock telling a joke about The People Vs. OJ Simpson, as the camera cut to awkward reactions from the crowd.
It didn't go over very well with the audience then either, and after his "flat" hosting effort that year, he wasn't invited back.