When the bike patrols suddenly ended in downtown Los Angeles' arts district last month, junk began to pile up against the curb on Seaton Street.

Over on Mateo Street, a trail of aqua-blue chips from shattered car windows glittered along the gutter.

"It's like they got the memo the guys were gone," said actress Dawn Cody, who lives in the arts district.

The private patrols were run by the neighborhood's business improvement district — one of 10 downtown and 39 throughout Los Angeles. The city authorizes them to collect fees from property owners to fund services that City Hall can't or won't provide.

Many say the improvement districts have transformed downtown by enlisting cleanup and security crews and promoting the once-abandoned area to new residents and investors.

But critics say that in the newly thriving central city, some business improvement districts have become bloated bureaucracies whose job can be done cheaper and better by others.

"There is no need to spend $1.3 million per year to keep the neighborhood clean," Yuval Bar-Zemer, who developed the arts district's Biscuit Company Lofts, said in an email. "We could get it done in a fraction of the cost, and we may be able to get the city to contribute the baseline services that we all deserve."

After Bar-Zemer and other property owners took the city to court, a Los Angeles Superior Court judge ruled in December that the improvement district had overstepped its authority by sponsoring bus tours and other marketing efforts aimed at outsiders.

Improvement districts are supposed to be voluntary pacts that serve property owners. They're not supposed to morph into mini-governments serving the community at large.

The arts district group was ordered to disband in May. Overnight, the men and women in the bright blue shirts who scrubbed graffiti, washed sidewalks and deflected petty crime vanished.

The court ruling comes as improvement districts in California are facing increasing legal challenges. An appeals court in 2011 ordered the city of San Diego to disband a district in Golden Hill, a historic working-class neighborhood near downtown. Two more legal challenges to similar districts were filed last year, also in San Diego.

Los Angeles paid $580,000 last year to settle a suit by the owners of Angelus Plaza, a nonprofit senior complex on Bunker Hill, over improvement district fees. The complex's owners have a similar claim pending over a senior housing project in San Pedro.

Some leaders fear the arts district ruling could be a setback for downtown's ongoing reincarnation as a signature entertainment and residential area.

The Downtown Center Business Improvement District devotes 27% of its $5.4-million budget to economic development, communications and marketing, said Carol Schatz, who heads the group. The tours and websites that improvement districts sponsor were instrumental in bringing bars, restaurants and boutiques back into downtown, Schatz said.

"Even Staples, unbelievably, wasn't a slam-dunk," she said. "We helped to facilitate innumerable deals."

The arts district lies between the Los Angeles River and Alameda Street, on the eastern edge of downtown.

The punk artists who took over its old brick warehouses decades ago were in the first wave of the reoccupation of the central city, and the anarchist impulse lives on. Some residents disdain the improvement district officers for hustling transients along too roughly, saying a little bit of grit hones the creative edge.

The dispute reflects growing pains that have emerged since luxury lofts and high-end restaurants popped up amid cold storage businesses and a jeans manufacturer.

The property owners who brought the suit said they were added to the improvement district against their will in 2011. They also said the improvement district's role in turning the area around was exaggerated.

"It is the development and revitalization of old buildings that improves the area," Bar-Zemer wrote, "not a privately managed group of kids on bikes."