Therein lies the dilemma for officials trying to get a handle on a growing menu of trolleys loose in their cities: how to ensure that residents understand that it's illegal to remove them from store grounds, while also persuading managers that it's good business to keep them on their property.
Several California cities recently enacted, or started studying, measures that penalize retailers for not keeping a closer eye on their carts. Los Angeles City Councilman Tony Cardenas plans to propose such a law this week.
Los Angeles officials have tried in vain for years to control abandoned carts. The problem is widespread in districts with lots of multifamily housing and in areas with many lower-income and elderly residents who don't own cars and "borrow" carts to carry things.
But it doesn't stop there.
In Sunland-Tujunga, a red plastic Target cart and a Ralphs cart bumped together recently along the banks of the boulder-strewn Tujunga Wash, marring the otherwise picturesque mountain backdrop.
Store managers said they pay a cart retrieval service to pick up the trolleys, but acknowledged they're unsure how many carts they have in their inventories or how many go missing.
"It's very difficult to get away from that habit -- people are used to it," said Javier Felix, store manager of a Ralphs in Sunland.
After 5,300 carts were collected in six months in his central San Fernando Valley district last year, Cardenas called store owners together for a meeting, where they conceded that they had "picked up more than 10 times" that number during the same trial period.
"Constituents, and my staff, have seen close calls that turn our stomach, like when we see little kids playing with these on sidewalks," Cardenas said. "You might see a shopping cart next to a couch, or next to a refrigerator, and before you know it, it's a magnet for illegal dumping."
Cardenas devised a measure, with help from store managers, that would require businesses that lose a certain number of carts during a specified period to install electronic systems to prevent people from taking trolleys.
But a trade group representing grocery stores said cart containment systems are expensive and suggested that Los Angeles and other cities enforce an existing state law that prohibits the taking of carts.
"There are three victims involved in cart theft," said Dave Heylen, a spokesman for the California Grocers Assn. "It impacts the retailer, it impacts those who live in the local communities, and then it puts a burden on the city."