unite nations leaders france italy unite kingdom urge social media company wednesday swiftly remove terrorist content internet aim stop upload first place tech company make significant progress issue need go fast reduce time take remove terrorist content online british prime minister theresa may say speech unite nations general assembly world leaders new york say need increase significantly efforts stop extremist content upload first place french president emmanuel macron italian prime minister paolo gentiloni late push separate event host may content remove swiftly must do one hour content must identify analyze withdraw avoid broadcast widely experience show possible say macron speak interpreter real battlefield hearts mind web gentiloni say say economic privacy issue hurdle process also know aware fact battlefield relevant reduce ambition difficulties several websites across internet list ingredients make bomb instructions use vehicles attack pedestrians online retailer amazon.com say wednesday review website investigation find could help users buy ingredients make bomb use frequently buy together customers buy also buy feature european union threaten legislation internet company good police available web remove content within hours indeed stop appear internet first place pose enormous technological scientific challenge say kent walker general counsel alphabet inc google haystacks unimaginably large needle small constantly change walker speak behalf facebook inc microsoft corp google subsidiary youtube twitter inc members global internet forum counter terrorism create june pressure governments europe unite state spate militant attack aim share technical solutions remove extremist content work closely counter-terrorism experts walker say august 2015 june 2017 twitter suspend almost million account promotion terrorism use technology artificial intelligence allow facebook root terrorist cluster may macron gentiloni push quick removal extremist online content