Yup, I own a few Benchmades and aside from one with a physical lock[1](which happens to be a "spring loaded, assisted knife", which is not illegal) all of them

Yup, I own a few Benchmades and aside from one with a physical lock[1](which happens to be a "spring loaded, assisted knife", which is not illegal) all of them could be considered gravity knives by nature of their locking mechanism. However things like Kershaw's SpeedSafe[2] and other assisted knives are totally legal and exempt, it's crazy. The general wisdom in the knife community is to not make a scene or rock the boat if you've got any pocket knife on you and UNDER NO CIRCUMSTANCES use a pocket knife to defend yourself(even under thread of life or limb). There's a metric ton of laws about using knives and weapons(even in self defense, largely tied to gang enforcement) and prosecutors tend to aggressively pursue them. In a lot of cases you'd be under less legal jeopardy drawing a pistol with a CCW than a small pocket knife. Knife laws are also enforced on a per-city basis(aside from the assisted knives which are generally state-level). So one town might have a length limit of 3" where the next town over might be 3.5". It's almost impossible to not run afoul of some local ordinance. [1] http://www.benchmade.com/emissary-3-5-family.html http://www.benchmade.com/emissary-3-5-family.html [2] https://kershaw.kaiusaltd.com/technology https://kershaw.kaiusaltd.com/technology