From MSNBC.COM:

Suspicious devices part of marketing plan

Promotion of ‘Aqua Teen Hunger Force’ cartoon closes Boston bridges

BOSTON - At least nine electronic devices planted at bridges and other spots in Boston threw a scare into the city Wednesday in what a cable network said was a marketing campaign for a late-night cartoon.

Highways, bridges and a section of the Charles River were shut down and bomb squads were sent in before authorities declared the devices were harmless.

“It’s a hoax — and it’s not funny,” said Gov. Deval Patrick before the objects were determined to be part of an ad campaign.

(more here)