PHNOM PENH: It is a chaotic and dusty artery that links Cambodia to Vietnam through the frontier town of Bavet. Dozens of workers pack into the backs of trucks, shipped to and from factories and building sites. Children play beside guarded compounds, rubbish burns near golden casino entrances and luxury vehicles pass stark worker dormitories. There is one thing that stands out among it all: the flood of advertising for online gambling, everywhere despite it being illegal in Cambodia.