A US broadcasting firm and a marketing company have agreed to pay $2m after a "guerrilla" advertising stunt that sparked bomb scares across Boston.
The electronic devices were meant to advertise a cartoon
The city went on high alert last week, closing bridges and roads, after 38 flashing devices were discovered.
One of the battery-powered signs - meant to advertise a TV cartoon - was destroyed in a controlled explosion.
It is not clear whether charges against two men for allegedly placing the devices will be dropped after the deal.
Sean Stevens, 28, and Peter Berdovsky, 27, pleaded not guilty to placing hoax devices and disorderly conduct.
The devices had also been placed in nine other cities as part of the publicity campaign, without causing any problems. They had been in place for several weeks before the Boston alert.
US TV giant Turner Broadcasting Systems and an advertising firm, Interference Inc, agreed to pay $2m (£1m), half of which is meant to cover the security operation and the other $1m as a goodwill gesture.
Mr Stevens and Mr Berdovsky deny the charges against them
"We understand now that in today's post-September 11 environment, it was reasonable and appropriate for citizens and law enforcement officials to take any perceived threat posed by our light boards very seriously and to respond as they did," Turner said in a statement.
It said it was reviewing its marketing policies.
"I am happy this entire ordeal has been put to bed with this latest agreement. Turner broadcasting has been extremely co-operative," Boston Mayor Thomas Menino said in a statement.
The signs featured a character from the adult-themed late-night show Aqua Teen Hunger Force raising its middle finger.