The challenge of gutter oil is so rampant which the countrywide security apparatus started a marketing campaign in 2011 to stamp out the "4 black pests" (打四黑除四害) — black workshops, black factories, black markets and black gambling dens. There was some drilling to insert cables but any dust was cleaned https://wildbookmarks.com/story20055633/facts-about-cctv-installation-in-wakefield-revealed