 To counteract this assumed threat, De Beers introduced strip searching, whereby workers leaving the mines at the end of a shift would be undressed and searched for diamonds.A more extreme measure was taken in the early 1880s by De Beers, when the company introduced corporate compounds.These enclosed compounds were built in the style of open-air prisons, where workers were required to live by the terms of their contract, in exchange for food, accommodation, and cheap beer provided by the company.