And on Sunday, Brent Jacobsen witnessed something he's sure was a crime.
"I was just hanging out with my kids at the park taking pictures of them, so I had my camera there, and this white pickup truck just starts driving up Riverside [Drive] taking signs," said Jacobsen, president of the city's lifeguard management association.
Since he had his camera, Jacobsen took photos of a man with an armload of signs, a woman waving from the driver's seat of the truck and the truck's license plate.
While it's unlikely city workers would vandalize signs, both cities do have rules about signs on public property and periodically remove them.
In Newport, no signs are allowed on city property, including the medians of city streets. City employees take down signs about once a week from major thoroughfares, and candidates can retrieve them from bins in the city utility yard, City Manager Homer Bludau said.
In Costa Mesa, city code allows campaign signs from Friday morning to Sunday night in the parkways on public streets, but each candidate is limited to 10 signs city-wide, code enforcement office specialist Rachel Gamboa said.
That doesn't account for all the disappearances. Newport Beach council candidate Michael Henn recently said he's had to buy more signs after his disappeared and didn't turn up in the city's bins, and Jacobsen said the man he saw was taking signs for people or initiatives that don't support Measure X, but leaving pro-X signs in place.
It doesn't appear that anyone has called police about the sign problems. Costa Mesa police said they had one complaint some time ago, and that's it. In Newport no official complaints have been filed, police said.
But everyone has a theory about what's going on, and people are pointing the finger at everyone from entire ethnic groups to individual campaign consultants.
It may happen in every election, but that doesn't make it any more palatable to Margolin. He recommends a public spanking for the culprit.
"This is just not acceptable behavior in our society," he said.