while this is still not quite the subject under discussion (security+bugs), it's at least much closer and i can show you the problem i pointed out originally: if all buildings are ugly (cf. all bugs are security bugs) then just because a building is ugly, it doesn't stop being a building, does it? but then we have a building which is both well defined to be a building and not well defined to be ugly, despite being in one and the same set. that's the logical fail because if these two sets are declared to be equal and one set is well defined (i.e., we can tell what is a software bug, or what is a building) then so must be the other set as well (if we want the original claim of their being equal to stand), in contradiction to what tialaramex claimed. the obvious resolution of the contradiction is to realize and admit that not all bugs are security bugs but for LWN's resident security experts hell would have to freeze over for that to happen ;).