In this environmentally sensitive city, surrounded by water on three sides, the sight of 10,000 red balloons drew a less than festive response.
"OK, that seems like a dumb idea because how could they not know these are going to go in the water?" said Eddie Codel.
They were launched from the Game Developers Conference at the Moscone Center attached with flyers to hype an upcoming video game.
"A see a lot of birds walking on the Embarcadero eating anything and if they swallow one of these balloons, you know, it can kill them," said Robert Comacho.
The flyers trace the balloons to the video game maker THQ and GameStop, a retail video game outlet. GameStop quickly distance itself from the public relations fiasco saying the stunt was created by THQ.
"This is latex. I can smell it. I can taste it. It's definitely latex," said Codel.
But THQ says the balloons "...were made from 100 percent organic product and are 100 percent biodegradable."
"It smells nasty. It smells like balloon, like a normal balloon," said Comacho.
"It can take a very long time for even biodegradable material to degrade when it's in the cold waters. It doesn't necessarily mean they won't be mistaken for food sources and cause damage," said Deb Self from Bay Keepers.
While it's not illegal to launch balloons in San Francisco, it's a violation of the Federal Clean Water Act if it lands in the water, even if it is biodegradable. The EPA is now investigating.
"The Clean Water Act doesn't discriminate or distinguish between what you've thrown in the water. We do need to show, and we would, that it violates and we haven't done that yet," said Jared Blumenfeld, an EPA regional administrator.
A sample of red balloons in the water is all that it will take. Aside from the EPA, the U.S. Coast Guard and the city and county of San Francisco are also investigating this incident.