Why are gravity knives illegal?

Hi guys! These knives JUST came back in stock here: http://bit.ly/reate-exo-m. Why are gravity knives illegal? Featuring the Reate EXO! Gravity knife laws date back to the 1950s where lawmakers worked to associate them with criminals, gangsters and minorities. Basically, lawmakers wanted to frighten the public about these dangerous blades and then exploit that fear for political gain. Recently, gravity knives have seen a renaissance in the past couple of years with model releases like the Reate Knives EXO. Furthermore, laws are becoming more lenient in certain states.