Craig Mosbaek went to bed Friday night assuming nothing was amiss outside his house near SE 30th and Division, hardly a hotbed of mayhem and trouble. He woke up the next morning to something a little startling and a lot annoying.

His lawn sign endorsing Portland's water fluoridation measure—Mosbaek is a public health consultant, former state official, and occasional volunteer for the campaign—had been torched at some point in the night. It was there when Mosbaek walked his dog around 8 pm Friday. This is what he saw in its place the next day:

"I woke up and went outside and saw the sign wasn't there," he says, "and I looked closer and you could see the ashes on the grass below the sign and a little bit of melted plastic stuck to the metal supports for the sign. I found a pack of matches close to it, too. I figured that's what happened."

Mosbaek says he called the cops. He'd been hearing from neighbors on both sides of the fluoride debate who've had signs stolen. Almost everyone has a story about that. Someone in my neighborhood found a stack of "no" signs dumped down by the Willamette River. In case you haven't heard, fluoridation has been incredibly divisive. But this was a little bit different, a little more intimidating.

"I wasn't worried about the house burning down," Mosbaek says. "It was more that someone was trying to take away our free speech rights."

Police spokesman Sergeant Pete Simpson confirms a report was taken and that Mosbaek told us what he told the cops. Simpson also says he's heard a lot of reports "anecdotally" about sign thievery, more so than in other elections, and that "this is the first time I can remember hearing about signs being damaged."

It's something to keep an eye out for. Simpson says cops don't plan on investigating, that there's not much point given the bigger crimes the police bureau is working. He says one of strange things about sign crimes is that the signs are usually owned by the campaigns and on loan to supporters, so it's not always clear who the victim really is.

But he also says officers will always come out and take a report. Even if it's just sign theft.

"We want people to report theft," Simpson says. "And if you see someone, call the police and get the police there."

Mosbaek put up another sign. He's not on the fence about fluoridation.

"I'm pretty supportive," he says. "The science is clear that it's safe and effective."