Housing buyback referendum campaign goes into second phase The Expropriate Deutsche Wohnen & Co initiative started collecting signatures today. The support of 170,000 Berliners is needed to force a referendum. Artikel anhören Watch out: the ghost of expropriation future's about. Berlin - Shortly after midnight, the "Expropriate Deutsche Wohnen & Co" campaign began collecting signatures for the second phase of its petition for a referendum on the expropriation of flats owned by large property companies. Their aim is to collect signatures from at least 7 per cent of Berliners who are eligib...