Microsoft, Facebook, Twitter and Google have agreed to up their efforts to tackle extremist content, pledging to remove such posts within hours of them going online. The pledge from the world's largest tech companies was decided during a two-day meeting in Italy between the firms and representatives of the G7 nations. The primary aim, according to officials, is to remove jihadist content from the internet within two hours. The G7 officials also urged the companies to develop better detection tools and to make sure all removed material is reported to authorities.