online. and u.s. officials fear that some of them could be inspired to carry out attacks here. >> it really is an expansion of how the internet has been used, frankly, for several years now both in recruitment and radicalization of young people to join terrorist groups. >> reporter: the men believed to have been in touch with one of the texas shooters is back online encouraging new supporters. the british-born isis recruiter posted his contact information on twitter for anyone who wants to quote, bake a cake a well-known code phrase for building bombs. >> group likes like isil or al qaeda now are calling publicly for attacks in the west of people who they have never recruited, specifically, they have never trained. someone could decide on their own to answer that call with little or no notice to our intelligence community.