Anders Sandberg thinks through the ethical issues raised by scientists creating a new strain of potentially pandemic bird flu for lab research. Iain Brassington doesn't think terrorists would want to use bioweapons in the first place:
[I]f you let off a bomb or some nerve gas, you’ve got the effect right there: Here we are, here’re our demands, BANG!, We really mean it. With something like flu… well, it could be days before anyone even notices what you’ve done, if they notice at all; and then you have the task of persuading the public that the strain of illness really was yours. We already have the phenomenon where shadowy groups claim responsibility for other people’s bombs; part and parcel of terrorism is that various nutters will appear to claim that they did it. Translate that to bioweaponry, and the situation becomes ludicrous: Here we are, here’re our demands, Atishoo!, We really mean it… No, honest, it was us, stop laughing, come back.
The Dish 