Turner said the devices have been in place for two or three weeks in Boston; New York City; Los Angeles, California; Chicago, Illinois; Atlanta, Georgia; Seattle, Washington; Portland, Oregon; Austin, Texas; San Francisco, California; and Philadelphia, Pennsylvania.
However, only in Boston did the light boards create such a furor. In Seattle and several suburbs, the signs were removed without fuss, according to The Associated Press.
"We haven't had any calls to 911 regarding this," Seattle police spokesman Sean Whitcomb told AP on Wednesday.
Police in Philadelphia told AP that authorities had confiscated 56 of the devices. In New York, a street was shut down for 45 minutes after two of the devices were found on an overpass, the New York Post reported. In all, 41 of the devices were found in the Big Apple, according to the newspaper.
In Boston, however, state, local and federal authorities shut down the Boston University and Longfellow bridges, and blocked maritime traffic from the Charles River into Boston Harbor. Bomb squads scrambled throughout the city and its suburbs, snarling traffic and mass transit in the city.