Looks like Foursquare is running a badge as an award for Halloween season swarms. Kinda creepy that I won it when I checked into a Hurricane. Large weather patterns are featured as a checkin location often enough on Foursquare that it should be its own category. Maybe a Stormchaser badge?

Congrats! Your recent check-in at Hurricane Sandy just unlocked the Zombie Swarm badge!
Ermagherd! This place is swarming! At least five Boy Scouts are in line for the bathroom (thanks a lot, Wes Anderson), there’s a Gangnam Style flash mob coming your way, and… is that a slutty Big Bird making out with Bane in the corner? Shut it down.