dispensaries, driving snow, wind or cold didn't deter the faithful. the line, in the hundreds, all day long. what does today feel like? >> um, freedom. >> reporter: with new freedom comes new responsibility. signs are everywhere, the dos and don'ts of pot, illegal for under 21 to light up. public health officials fear abuse. at greatest risk, kids. >> over half the admissions for addiction in this state, in kids under 15 and teenagers for marijuana. >> reporter: drivers can get busted. the legal limit, five nan grams of thc in your blood. i don't smoke, but if i had pun puff, does it put me over the limit? >> yes. >> reporter: one puff? >> yes. >> reporter: for how long? >> it's unknown. by two hours it will probably be gone.