Credit: Transport for LondonAn ad for Transport for London’s new ‘Act Like a Friend’ campaign has been banned for reinforcing negative stereotypes about black men.The Facebook ad, part of the campaign that encourages people to intervene safely if they witness sexual harassment or hate crime on the TfL network, showed a black male verbally harassing a young girl accompanied by a white male friend, who sat down close to the victim ‘boxing her in’.