I learned a long time ago to be very cautious about taking classified sources too seriously. Technical stuff (classified) is often very good but at the same time very limited. Today, you can get stuff as good or better than we got during the Cuban Missile Crisis from Google Earth! But you still can't look inside a cave in Afghanistan. HUMINT from espionage nets is essential for denied areas (like the old USSR) but a good reporter usually gets better stuff than official reporting whether from the Embassy or intel agencies in relatively open societies. One problem is that the foreign correspondents are fewer than in the old days and don't have enough time on the ground to develop the kinds of sources their predecessors did. That said, there are many more unofficial observers on the ground today and they have access to the internet. Still, you have to be careful of using what you find on the net.

Bottom line is that some of the best stuff on Al Qaeda, for example, is from open sources like Peter Bergen, Rohan Gunaratna, and Raymond Ibrahim's The Al Qaeda Reader. Note that all the world's intel agencies were surprised by the Mumbai attacks but I wouldn't be shocked to find that they were predicted in some open source (I have no knowldge that they were but it would not surprise me).

Cheers

JohnT