The flag flying above number 10 Downing Street, the British Prime Minister's residence, has been lowered to half mast. <br /><br />UK Prime Minister David Cameron, Conservative Party leader, was quick to pay tribute to his predecessor, calling her a "great Briton".<br /><br />But Thatcher's legacy is disputed, with some celebrating her passing.<br /><br />Al Jazeera's John Terret reports.
