some more bogus and dangerous tactics being taught

Here is another look at some of the stuff being taught out there for "knife-defense".

Key points are:
- if the technique relies on you knowing the person has a knife, it sucks.
- if the technique only works on a cooperative "attacker" role-player, it sucks even worse

Enjoy: https://www.youtube.com/watch?v=Q89SdwACUx4&feature=youtu.be