emergence of what they call the individual actor or small cells. the problem with that is that it is very hard to intercept communications. they don t necessarily use the traditional methods of talking to each other, which has allowed us to intercept or to block theses oe past. so, i don t want to go down one road as to a specific group. but this has been seen as the emerging threat. the individual or small cell which is very hard to infiltrate by law enforcement. in this case the fbi, shepard. shepard: catherine herridge, our intelligence correspondent live in washington. we will be back to her as events warrant. on the left-hand side of your screen the westin hotel advertisement there is actually the scene of a news conference which will happen clearly at the westin at coply place in boston which frankly isn t far from the spot where all of this happened. authorities were to brief us 13 minutes ago. that s been displayed for a few minutes.