What could
possibly go wrong with this?

NYPD, Brookhaven Releasing Harmless Gases in Subway for Chemical Weapon StudyThe NYPD and Brookhaven National Laboratory will begin studying air flow in the subway systemTuesday, Jul 9, 2013 | Updated 9:29 AM EDT
The NYPD is releasing harmless gases into the subway system during the morning rush beginning Tuesday to study how chemical weapons could be dispersed through the air.
Police, working with Long Island's Brookhaven National Laboratory, were spotted placing air-sampling devices in specific areas on the street and within the subway system across the five boroughs. Several researchers spent Tuesday morning outfitting the Columbus Circle subway station with the devices.
Researchers will track the movement of harmless tracer gases called perfluorocarbons.
There's three more paragraphs to the story, which can be found here:
http://www.nbcnewyork.com/news/local/NYPD-Brookhaven-Gas-Subways-Chemical-Weapon-Study-Equipment-Installation-214692501.html?drI like the idea, because one can countless simulations in a lab and not find all of the nuances of the actual system. but, what if someone decides that this is a
perfect time to release some harmful gas and 'piggyback' on this drill? Or am I needing this emoticon:
