@cstross Presumably, you'd also design it to *only* target your enemies. Or, at least make it not target your allies.
The only kind of mad science supervillain who would create and release a bioweapon that inflicts brain damage in the least-obvious-to-its-victims way possible, to everyone *including themselves*, would have to be a complete and utter bonehead, or while experimenting in their lab have suffered some kind of brain damage that they weren't really awa.... oohhhhhhh!