Guests at the New York event were warned against taking photos by Vogue magazine's US editor, Anna Wintour, although the 'Boyfriend' singer was quick to break the rule, posing for a snap with supermodel Cara Delevingne shortly after arriving. <br /> <br />According to the New York Post, the editor's note prior to the ball read: <br /> <br />"The use of phones for photography and social media will not be permitted inside the gala." <br /> <br />Madonna also threw caution to the wind by sharing a variety of photos with her 3.7 million Instagram followers, including one with fellow female singers Katy Perry and Lady Gaga. <br /> <br />Captioning the picture, she wrote: "Girls night out.......... Kissing the Ring........Finally!#metball (sic)." <br /> <br />Reposting the shot on her own account, Katy Perry joked: "dropping our single tomorrow #stolethispicfromM#MONSTERCATREBELHEARTS (sic)."
