A cab driver from Northern Ireland has been arrested after pulling a gun on a passenger and threatening to blow his kneecaps off, and then pistol-whipping him.The 48-year-old taxi driver has since been arrested, for possession of, and intimidation with, a firearm. It has not been confirmed if the gun was real or fake, nor the reason behind the incident, although rumors circulating online indicate it was over a drug-related debt. The whole incident was captured on dashcam, which somehow ended up being posted online, to the incredulity of all.