I searchbarred, but nothing about actual running haha. Basically its a group that meets weekly, and one of the members is the "hare" for the week. They go out during the day and set a trail using chalk arrows on the sidewalk. They can make splits, where one trail suddenly ends, etc. And wen the run starts its a group of like 40 people all trying to figure out where the trail leads, because at the end is a bar, where 20$ gets you all the food and beer you want.
A friend brought me to the one in NYC last night, and it was crazy how much fun it was. The 4 mile course ended up being like 6 and a half, but survivable. They have a "ceremony" each week where the "virgins" ( new guys ) get introduced, chug a beer, etc. and give out random hilarious awards. All in all, the description I was given totally matched it. " A drinking club with a running problem "
http://www.hashnyc.com if you wanna actually learn a bit more, from what I hear there are clubs throughout the US and other countries.