While they may be used to hold others at bay, that is at the threat of damage.
They are intrinsically an offensive weapon, as they damage, not protect, which is what I think of when I think of defense. That is why I think it is funny. A shield I would consider a "Defensive Tool", or body armor, or armor plating. A projectile that damages flesh not so much.
ETA Not sending an email, don't need to sign my name
Edited, Jan 10th 2013 4:06pm by stupidmonkey