Vaccinations With No Feeling

Fox news was just reporting on research that has lead to the ability to give "shots" with fibers so small that they go undetected by human pain receptors. Everyone seemed so excited by this, however my first thought is I want to know when something is being injected into my body. This new technology could quickly become a weapon for the "bad guys" whether they be in another country or our own back yard. Once this technology becomes cost effective it could be slipped into hats, shirts, pants, socks, etc. and never felt by it's victims.