Rick Swinger has an odd hobby as a photographer. He likes to walk around his neighborhood with his camera jostling by his side, looking for disgusting things to photograph.

He doesn’t have to look very hard. Swinger has lived in Venice, an Instagram-famous beach town in Los Angeles, for 38 years. Just a block away from his two-bedroom condo resides one of the largest homeless encampments in Venice, where tents, sleeping bags, gallon-sized garbage bags, and random pieces of furniture litter the sidewalks.

The other day, Swinger found two brown splashes of feces and an orange mush of vomit not far away from his doorstep. He later uploaded those photos to “Stop Illegal Dumping in Venice Beach,” a Facebook group he created that now has more than 1,500 followers.

“Hepatitis A, anyone?” he wrote on the post, prompting upset neighbors to comment, “I see it all the time. Disgusting.” Another wrote, “Unfortunately for us, the thinking has changed and homelessness isn’t a crime. … What about our right?” Another simply commented, “Homeless people are kinda gross.”

When I visited Swinger in his two-bedroom condo, he showed me more pictures of street pollution that he’s saved on his computer. He says he’d much rather take pictures of sunsets, but he’s fed up with all the literal crap splattering his neighborhood and wants someone to do something about it. So he chases after scavenging rodents with his camera, advocates for more rat-proof trash cans, and attends public meetings to oppose projects such as homeless facilities that in his words would attract more “serial poopers” into town.

Swinger is what some homeless advocates and housing activists call a “NIMBY.” Short for “Not in My Backyard,” NIMBY is a pejorative term used to describe homeowners who oppose controversial development projects such as low-income housing or metro stops in their neighborhoods.

Few people self-identify as a NIMBY. Swinger despises that term—he says it mischaracterizes him as a wealthy racist who places property values above others. That’s not true, he says: He’s a 59-year-old formerly homeless guy who got a job and worked hard to buy the condo he now lives in with his Filipina wife.

Today he says “no” to homeless shelters and housing in his backyard, because “you’ll be a fool to say yes to [expletive for poop] in your backyard.” He says he too wants to help the homeless—and has many ideas on how—but not at the expense of neighborhood safety: “Once you take away sanitation, you take away civilization.”

Homeless activists say Swinger is painting a false narrative of the homeless population. Homelessness, they say, may be a drug or alcohol or mental illness or unemployment problem for some, but it’s a lack-of-housing problem for others in high-cost states. And many Californians are now demanding changes to the housing policy status quo that they say is making California a more inequitable, unsustainable place to live.

This status quo, they say, includes outdated zoning laws, NIMBYism, and cumbersome regulations, which prevent significant housing development from taking place, thus leading to extreme housing shortages, rent hikes, and displacement of mostly poor minorities.

These housing advocates are calling themselves YIMBYs—“Yes in My Backyard”—and they’re making their presence seen and heard in public meetings, city council elections, and social media. YIMBY groups are sprouting across the nation in housing-crunched cities such as Portland, New York City, Boulder, Boston, Minneapolis, and Austin, but the movement is particularly strong in California. Their unofficial slogan: Build, baby, build!