Choking traffic, causing pileups and even ambushing drivers, Venezuela's hordes of motorcyclists are an increasingly high-profile problem for the new government of President Nicolas Maduro.
Denounced in the media as a "plague,'' they provide essential, cheap transport but are often held responsible for anarchy on the roads and the terrifying number of homicides, kidnappings and armed robberies that beset the South American country.
Some also see them as shock troops of the late Hugo Chavez, who pushed through radical socialist policies during his 14 years in power before dying from cancer in March.
For many opposition-leaning voters, especially in wealthier areas, the bikers are the public face of the underworld.
Most of these "motorizados'' - a term that can be applied to almost anyone who works on a bike - in Caracas say they are just trying to scrape a living as taxis and couriers in a congested city that desperately needs them, and are being blamed unfairly for the crimes of a few rogues.
Maduro was handpicked by Chavez, but he only narrowly won the election to succeed him. He faces a huge test to crack down on the lawlessness often associated with the motorizados while still retaining their many working-class votes.
"They're a problem,'' Interior Minister Miguel Torres said, launching a strategy last month to control Venezuela's hundreds of thousands of bikers. "Not all of them, but there are lots who think they're in the old Wild West.''
Many behave atrociously, he said, riding on sidewalks, knocking off mirrors as they weave in and out of traffic, and hurling abuse whenever challenged. Some are involved in much more serious offenses, including abductions and drive-by shootings.
In recent months, funeral corteges of dozens of motorcycles have become regular flashpoints, with bikers creating gridlock in order to smash windows and rob drivers at gunpoint.
Venezuela suffers one of the world's highest murder rates, and violent crime is the No. 1 issue ahead of Dec. 8 municipal elections that are the first major ballot test for Maduro.
The government's new plan includes high-level meetings with motorizado groups to improve relations with the security forces and get them to agree to some basic rules of the road.
Officials are also trying to win over the bikers by building shelters so they don't need to huddle under overpasses when it rains - often strangling traffic to a single lane by doing so.
"Amigo motorizado...'' begins a list of rules at one of the shelters, beneath an overpass near downtown Caracas called La Arana, or The Spider. Using drugs or alcohol there is prohibited, the sign reads, as is the "continuation of strife or disputes.''
Most motorizados belong to motorcycle taxi cooperatives, which carry their fares as passengers, or to the army of messengers who work for businesses, government departments and individuals. The name is also used for the bikers in socialist red T-shirts who whipped up support at Chavez rallies.
Despite the motorizados' bad public image, the opposition knows it can't ignore them either - especially since they're often the only option to beat the traffic gridlock.
Politicians on both sides say the street-level intelligence provided by biker groups could help tackle insecurity.
"We don't want the neighbors to see them as a threat, more as people who help them solve problems,'' says one opposition leader, Ramon Muchacho.
His well-off, opposition-run district in the east of the capital, Chacao, has registered about 50 bike cooperatives, he says, and is adding more at a rate of around 10 every six months.
A stuttering government effort to register motorcycles has recorded about 300,000 so far. Local business groups estimate there are about a million.
The explosion in the number over the last decade is due to Chavez-era deals with China that flooded the country with bikes going for a few hundred dollars, and social programs that meant more poor people could contemplate buying their own transport.
For many of the motorizados, Chavez himself took on an almost God-like status. One embodiment of the motorizado culture during Chavez's rule was Franco Arquimedes, a popular Caracas motorizado leader whose followers helped ferry survivors to safety after devastating mudslides in 1999.
In 2002, they rushed to Chavez's defense when he was briefly toppled in a coup: their role in his homecoming went on to assume near-mythical proportions for many loyal "Chavistas.''
But in the years that followed, motorizado gangs also becamenotorious for attacks on an opposition TV station, and on opposition activists protesting at a square in Chacao.
In 2007, Arquimedes was killed by gunmen as he shopped at a butcher's in the capital's Cementerio district.
"They assassinated a true revolutionary,'' Chavez said.
Arquimedes lies in a modest grave known as the Tomb of the Motorizado at the El Junquito cemetery, where terraced plots cling to a steep hillside with grand views down the valley toward the gray-white towers of Caracas.
At a graveside nearby, a young motorizado and his girlfriend drink beer from a can in a brown paper bag, both wearing the ubiquitous cheap black plastic helmets that in many countries would barely pass as cycling gear. They've come to pay their respects to a friend killed in a crash.
Motorcycle accidents are so common they're often referred to in the press as a public health problem, and it is estimated that each hospital in Caracas admits at least 100 injured motorcyclists every week.
A large trauma ward at one is nicknamed by motorizados the "Bera Room,'' after a Chinese bike manufacturer. On the weekends, the number of admissions routinely doubles.
Prey for gangsters
Gas prices may be the lowest in the world, but Venezuela's annual inflation rate hit almost 50 percent in September, piling the pressure on Maduro to show economic improvements.
There's a wait-list of about a month for the small-engined, most popular bikes, which have almost doubled in price in about two years. Prices for parts have shot up too.
"Tires that were 500 bolivars a year ago cost 1,500 bolivars now,'' says Luis Amundaray, a 22-year-old motorizado at his home high on a hill in the capital's giant Petare slum. "It's difficult.''
Luis' father, Jose, 52, says the young mototaxi drivers are easy targets for gangsters.
"They kill them all the time to steal their bikes,'' he says, taking a seat in the living room beneath an iconic news photo of Chavez, drenched by the rain at his last election campaign rally.
According to Venezuela's national investigative police, the CICPC, about twice as many motorcycles as cars are reported stolen in Caracas. Many are taken violently.
Amundaray had his bike stolen one morning about six months ago, while he was in a Caracas office delivering a letter.
"I came out and it was gone ... I was lucky, I guess,'' he says with a shrug.
Rallies and resources
As the government seeks to engage the bikers, some of the more organized mototaxi groups are among those calling the loudest for clear laws. They argue that lives - and livelihoods - are at risk if an agreement can't be reached.
Big differences on key proposals remain. They include banning motorcyclists from freeways, a prohibition against late-night riding, and parking restrictions to stop bikers blocking the entrances to subway stations, hospitals and other buildings.
Officials also want to stop the common practice of motorizados' speaking on cellphones stuck into the side of their helmets while threading through traffic jams.
Moves to bar giving rides to children are particularly fraught: for every horrific tale of a crash, another barrio resident says there's no other option if they are going to beat the city's gridlock and get kids to school or daycare on time.
One proposal to stop drive-by shootings would ban passengers riding with motorizados, which would destroy the mototaxi business.
According to one study, as many as nine out of ten violent crimes in Caracas involve motorcycles. Last week saw just the latest ugly incident involving a funeral procession: a collision near the La Arana overpass led to a fight between a biker and a car driver, onlookers said. Both men had guns, and both died in the shootout.
In September, the headquarters of the national intelligence agency, Sebin, hosted the first of a series of meetings and workshops to discuss the way forward with motorizados. It also supports rallies like the one held this month in the plaza named after Franco Arquimedes in the tough San Agustin barrio.
Officials provided legal advice and bike registration services out of trailers set up near a graffitied basketball court, as a band played salsa and an MC threw high-visibility safety vests from the stage. The barrio's cable car, which Chavez opened in 2010, whirred quietly overhead.
"We'll approve whatever resources are needed, but you've got to help us by sticking to the rules,'' Torres, the interior minister, told motorizados last month. "Chavez taught us that the law is the same for everyone.''