[SoLiDUS]

Nanomachines are a very real possibility. If computers are intentionally
delayed and were already what we (at present) have, imagine the kind of
technology they're experimenting with...

It isn't a question of how... but when(?). This is when things will get VERY
interesting: could you create a weapon that could not be seen or smelled,
yet would kill every single black man in a room ?

Yup, you got it.