The trouble of gutter oil is so rampant which the nationwide protection apparatus commenced a campaign in 2011 to stamp out the "4 black pests" (打四黑除四害) — black workshops, black factories, black marketplaces and black gambling dens. There was some drilling to insert cables but any dust was cleaned up. https://ariabookmarks.com/story5636155/cctv-installation-in-wakefield-things-to-know-before-you-buy