In one of the videos, a man is shown threatening people with a weapon before being tasered and pinned to the ground by police officers. One unnamed onlooker shouts "You ain't no Muslim, bruv."
Shortly after the footage was posted, the British public and people worldwide joined forces to show their defiance against terrorism, with the hashtag #YouAintNoMuslimBruv.
Even the U.K. prime minister himself, David Cameron, weighed in, commending the unidentified individual at a speech in the Midlands, for saying "you ain't no Muslim, bruv."
Since the event, the hashtag has been used more than 108,000 times, according to social analytics search, Topsy.
The U.K. police are now stepping up their policing on London's transport systems as a result of Saturday's attack.
"We are treating this as a terrorist incident. I would urge the public to remain calm, but alert and vigilant. The threat from terrorism remains at severe, which means that a terrorist attack is highly likely," Commander Richard Walton, who leads the Metropolitan Police's Counter-Terrorism Command said in a statement.