BOSTON - JANUARY 31:  A runner exercises along the Charles River across from the Longfellow Bridge (R), which was one several bridge sites where police found suspicious packages that triggered a bomb threat January 31, 2007 in Boston, Massachusetts. Preliminary investigations lead police to suspect an ad campaign was the source of the hoax. Getty Images logo Getty Images 29 months ago

BOSTON - JANUARY 31: A runner exercises along the Charles River across from the Longfellow Bridge (R), which was one several bridge sites where police found suspicious packages that triggered a bomb threat January 31, 2007 in Boston, Massachusetts. Preliminary investigations lead police to suspect an ad campaign was the source of the hoax.