""There are 30 that are actually being looked at very closely indeed because they have got to the stage where they are gathering materials and doing things which could lead in fairly short term to doing something if they wanted to.
"This means that effectively about 2000 individuals are being monitored in varying degrees of closeness and probably about another 2000 loosely connected to them. The scale of this whole thing is quite dramatic."
That's 4000 people. But remember, the 7/7/ 21/7, and latest Muslim terrorists weren't even on the security services radar.