The head of one of Hong Kong’s largest taxi groups has denounced undercover vigilante operations targeting Uber drivers, saying enforcement should be left to authorities. Chau Kwok-keung, chair of the Hong Kong Taxi and Public Light Bus Association, responded on Monday to reports that people had been posing as passengers in recent weeks and hailing Uber rides, only to then call the police on those drivers. Uber operates in a grey area in the city, which requires vehicles offering ride-hailing services to have a hire car permit. Taxi driver unions have long called on the authorities to crack do…