One thing I can see happening is advancement in "sniffers" which might eventually operate under the guise, appropriately, of bomb and biological threat detection. We have heard of drugs of the NBOMe series being referred to as chemical weapons. Definitions... We can work with them and bend them. There are technologies on the horizon, I have heard, that will be able to penetrate solids, and alert for anything "dangerous" based on some ability to distinguish molecular make up.
I just hope we legalize my favorites (classics) before this, if it does happen, happens.