We are continually threatened by our government with the spectre of a terrorist "dirty bomb" using cobalt-60 or some comparable radionucleide. However, an actual examination of the problem¹ reveals that to yield a actual significantly dangerous level of contamination over any significant area, such a "dirty bomb" would have to contain sufficient cobalt-60 that the terrorists constructing and deploying it would be dead within a few minutes in its proximity. This poses, shall we say, logistical problems in gathering and assembling such a mass of radioactive material.
The conclusion from this appears to be that such a "dirty bomb" is, indeed, largely a pure terror weapon, to be feared primarily because ... well ... people are afraid of it.
Discuss.
Some references:
[1] The actual article was in New Scientist, if memory serves, but I can't find it online, so wandering upstairs to find the issue and verify that is somewhat moot.