A courageous passerby was sprayed in the face with a fire extinguisher while trying to stop yobs from looting a phone shop.
A CCTV clip showing the attack in Battersea has been released in a bid to encourage the passerby - and any witnesses - to contact police.
The footage was shown last night on a BBC Crimewatch Special featuring the violence and disorder across London.
It shows an innocent member of the public outside the Carphone Warehouse shop near Clapham Junction at about 10.20pm on Monday, August 8.
He bravely tries to stop a gang of thugs from smashing the shop window further but they attack him with a fire extinguisher, spraying it directly in his face.
Anyone with information should call the Operation Withern incident room on 020 8345 4142 or Crimestoppers anonymously on 0800 555 111.