Abstractly (generally, and on subject) - knife is a fast weapon.
But there are many types of Knives, Daggers, Stilettos, Kunai and such.
They should be analyzed properly then used appropriately, to protect.
After analysis and training i will carry such as a warning if possible, and if neccessary for protecting by fight, even kill.
Do not worry, i do not have anyone on a 'list to kill', it's only for a warning.
It's Human Right afterall, to be able to protect life of Loved ones and defend myself.