Close encounter clip nets fans
The three-minute film is featured on the Google Video website, which attracts millions of visitors a year, alongside footage of the Champions League final and the Eurovision Song Contest.
It shows a teenage girl being knocked to the floor in Fleshmarket Close after being hit on the back of the head by a heavy roadworks barrier.
A teenage boy is also shown being kicked and punched on the ground by six youths, before stripping off his belt and swinging it at the gang.
Detectives have studied the clip, which was posted on the Google Video site on March 10, but have been unable to determine when the fight took place. A crowd of onlookers watched the incident involving around a dozen people - believed to be aged around 16 or 17 - which erupted outside Alfie's hairdressers and the Jinglin Geordie pub.
Traders based in Fleshmarket Close said the area was frequently a flashpoint for violence and disorder.
They have asked the council to install CCTV cameras in the close, which runs between Market Street and Cockburn Street. The downloadable clip shows a teenage boy being viciously beaten on the ground by six other youths.
He staggers to his feet after having his shirt hauled off his back, and pulls off his belt to confront his attackers.
The youth then swings his belt towards the group and taunts them before returning with a roadworks barrier.
He tries to throw the barrier at his attackers, but instead the barrier falls short and lands on a teenage girl's head, knocking her to the ground.
A group of bouncers then appear in the close and chase after the youth, catching him on the steps as he loses his footing before the footage cuts out.
Two teenage girls are also shown caught up in the middle of the brawl, with one aiming a slap at another youth's face. She is eventually thrown to the floor.
Franco Fortucci, shop manager at Alfie's hairdressers, said: "There is always trouble in the close with people fighting or getting robbed.
"On Friday night, a man ran past a group of French students and grabbed one of their rucksacks. It doesn't surprise me that there was a fight of this kind.
"Two nightclubs, City and Massa, are just a few yards away, and the clubbers all spill out at closing time.
"I've often come to work in the morning and seen blood and broken glass on the ground.
"We campaigned to the council for years to have CCTV cameras installed but with no success.
"A lot of youths hang around at the top of the close and they can be quite intimidating.
"It definitely affects our business as people can be worried about coming down here.
"All the little recesses in the close are used by drunks and down-and-outs too."
A police spokeswoman said: "Detectives have studied the video but we were unable to ascertain the time or date when this incident occurred. We have received no complaints from any victims.
"If anybody wishes to make a complaint then police officers would be happy to talk to them."