By means of broadcasts from Britain, the French Resistance found a voice that could be heard on the continent, serving to counter the Nazi propaganda broadcasts of Radio Paris and Radio-Vichy. Realising the negative effect that it had on their occupation, the Germans quickly prohibited listening to Radio Londres. Radio Londres also encouraged rising up against the occupation, including De Gaulle's calls to empty the streets of Paris for one hour, demonstrations, and the preparation of D-Day, or the V for Victory campaign, involving drawing a V sign on walls as an act of subversion.