Ho notes that policemen often have to associate with informants from the criminal world. Many people, like operators of illegal gambling or sex businesses, try to get close to police by posing as legitimate businessmen or by getting in tight with local politicians.
何明洲指出，以基層員警來說，為了要破案，與犯罪邊緣的「線民」交往仍是獲取情報的來源之一，許多如賭博性電玩、特種行業等業者，會化身為商人或政要等「白道」，刻意與警方接近。