That also leads into 'what famous Bostonions were those to strike a deal with the fey?' was it Paul Revere?
Edit: and about dunkin's in Boston, one of the guidebooks I ran across last year said that in the 36 mile area comprising of the 'city of Boston' there are 64 Dunkin Donuts.
Paul Revere was a silversmith, so maybe there's a werewolf connection?
The footprint of any Dunkin' Donuts within 101 miles of the geographic center of Boston is accorded neutral ground.
Or
Built into the foundation of every Dunkin' Donuts is in the Boston area is loadstone that functions as a sink for the magical energies trapped by the Boston area roads. The Boston Freemasons have enchanted items that also scoop up negative magical energies as they are carried around the city, which can then discharge in to the loadstones. The freemasons have many members in the Boston PD, the folks who run the trains, construction workers, and truck drivers.