For decades now, that cringe-worthy hissing sound heralding the presence of nitrous oxide dealers has permeated the parking lots of jam band shows. Neo-hippie burnouts and preppy Trustafarians alike line up to buy balloons filled with the gas for $5 a pop, then drop to the pavement, hit their heads, and start liking String Cheese Incident. It's a revolting scene, one that's now become familiar to concertgoers in NYC, where the "Nitrous Mafia" brazenly sets up shop on the sidewalk outside such venues as Terminal 5, The Music Hall of Williamsburg, and Brooklyn Bowl. How do they get away with it?

This week's loooong Village Voice cover story takes a grotesque look inside their booming business. The DEA doesn't consider nitrous a controlled substance and doesn't regulate it, so it falls under the purview of the FDA, which regulates it as a food-grade propellant, medical-grade gas, and prescription drug. It's illegal to purchase and sell nitrous for the purposes of getting high, but most states, including New York, treat it as a misdemeanor. And as the Voice reports, it isn't even on some cops' radar; some of them think it's helium, which may explain why we saw an NYPD car cruise right on by a crowd of nitrous buyers and sellers outside the Music Hall of Williamsburg last year.

There's now some push-back in the jam band scene against the dealers, who are seen as more parasitical than your average goo ball-slinging hippie. "I began noticing that all the people selling balloons weren't nice hippie kids trying to go from show to show," one fan, Justin Heller, tells the Voice. "It became clear that they were a bunch of thugs trying to make money." Another says, "These guys don't even know who Jerry Garcia is, and they never will." One EMT remarks, "I've watched so many young people crack their heads and faces open that I have personally stopped providing emergency first aid." The stuff is called "hippie crack" because of its addictive qualities (and brief high), and the fields of every concert festival are typically littered with balloons, "like bullet shells on a battlefield," as one head put it.

Yep, it's a war out there, and the Nitrous Mafia isn't afraid to fight back with knives and guns; reports of nitrous dealers beating up security guards and other dealers in turf wars are legion. Their main enemy is The Wrecking Crew, a loose affiliation of Dead Heads who recently scored a minor victory by kidnapping one of the Mafia's nitrous tanks and filming a YouTube hostage video, during which the precious gas was released into the open air like the blood of so many hippie infidels.