HONOLULU -- An appeals court is considering an argument that could end Honolulu's ban on aerial advertising and lead to aborted fetuses displayed off Waikiki.

An anti-abortion group said it has found a weakness in Honolulu's sign law big enough to fly a plane through. If the group wins, aircraft will bring beachgoers images that are intentionally disturbing.

The group that drives a truck with a display of an aborted fetus around Oahu would like to show the same sort of pictures from the air. It's an idea that many seem to oppose.

"It's offensive to a lot of people and it's not something you want to see," said Naomi Salomon, a downtown worker.

"It just clutters up the sky and creates a lot more hazards in the long run," said Brandon Chang, who also works downtown.

Honolulu's aerial advertising ban may not be airtight. It allows identifying names, logos and trademarks.

Pro-life lawyers told the 9th Circuit Court of Appeals Monday that it's illegal to allow that kind of aerial advertising, while banning its political message against abortion.

"So what in effect Honolulu is doing is they are providing greater protection for a form of commercial speech and banning all political speech and you can't do that under the first amendment," Center for Bioethical Reform attorney Robert Muise said.

If it wins, the Center For Bioethical Reform said it will blow up the pictures on the panel trucks to three times their size to make a banner that can be towed by aircraft so that thousands of beachgoers will see it.

City lawyers concede that aircraft could be used to advertise.

"This organization or any other organization can own a plane and can put their name on it," city attorney Jon Van Dyke said.

However, city lawyers said a banner behind a plane would still be illegal.

The Center For Bioethical Reform also argued that the city ban is illegal because federal law allows aerial ads.

The three appeals court judges left without comment. The court could take months to issue a ruling, which the losing side would likely appeal.