(CNN) -- It's known as the City of Light, but it risks becoming known as the city of the light-fingered.
Paris, the most visited city in the world by many counts, has been suffering a spate of pickpocketing -- and one of its main targets appears to be that relatively new group of tourists, the Chinese.
Petty crimes against Chinese nationals have jumped 22% in the city this year, according to Paris police.
Chinese visitors are thought to be particularly tempting because of a cultural preference for carrying cash over credit cards, the South China Morning Post reported.
They could also often be distracted more easily than some more experienced tourists.
Outraged visitors to Paris -- as well as Parisians themselves -- have posted warnings against the pickpocketing epidemic on Twitter.
"The annual August exodus from Paris has begun, the 7th arrondissement is deserted, only beggars, pickpockets ... and tourists [remain]," reads one post.
Another tweet warns, in French, of the latest pickpocketing technique: a thief pretends to be disabled and asks for your seat on the metro, only to relieve you of your possessions as you clumsily swap places.
A further post succinctly sums up the pickpockets' recent nationality bias: "Chinese tourists hate credit cards; French pickpockets love their cash."
Tourists from China not only often trust cash over cards but also, along with Russians, are among the biggest spenders in Paris -- and they often spend indiscreetly.
"I, and many people I know, have often been approached by the Asian tourists thronging outside the Louis Vuitton store on the Champs-Elysées, who approach you with cash to buy bags for them, as the store limits each customer to two," Paul Roll, director of the Office du Tourisme de Paris, told the Telegraph.
Parisian businesses are worried the risk of theft might drive Chinese travelers elsewhere.
The number of visitors from China to Paris last year, 1.4 million, was 23% up from 2011, the SCMP reports.
The city is a favorite destination among wealthy Chinese.
But a group of luxury retailers, including Chanel, Louis Vuitton and Hermes, recently warned that top spenders would visit London or Milan instead, if Paris came to seem too risky.
French officials have acknowledged the pickpocketing surge, putting 200 extra police on patrol around top tourist attractions and publishing a "Guide to Staying Safe in Paris" in Chinese, Japanese, Korean and Spanish -- one of several such guides acknowledging the extent of the problem.
The Paris police advice goes little beyond the need to be vigilant, but it does warn against carrying a backpack -- which can easily be pilfered because it's usually out of direct view.
It also says some thieves in Paris are impersonating police and asking for ID and proof that tourists are carrying money, which they then try to snatch.
Perhaps the most widely noted pickpocketing technique is for thieves to approach marks at cash registers, asking if they can help with a "petition."
As they loiter, they note the customers' PINs, then follow them and pickpocket their cards to withdraw money themselves later.
Copy your passport
The U.S. embassy in Paris also publishes an anti-pickpocketing guide.
"Make a copy of your passport, and front and back of everything that you have in your wallet," is some of its less obvious advice.
"Ladies," it says, "only carry purses that zip."
The guide also warns against another pickpocketing technique -- the metro "crush and grab," whereby a bunch of fellow "passengers" jostle you and pick your pocket as you get on or off a train.
Spilling water or ice cream on a potential victim is yet another method. Profusely apologizing, one of a pickpocketing pair will vigorously dust you down after the fake accident, while a collaborator steals your wallet or camera.
Don't wear shorts
So recognized is the Paris pickpocketing problem, that even TripAdvisor has a dedicated page of advice. It recommends the BeSafe smartphone app, created by a pair of French students, which collates data from police reports to display the most crime-prone areas in Paris in real time.
It also suggests how not to look like an obvious tourist.
Use the small "Paris Pratique" guide, it says, favored by French visitors to the city, rather than a large foldout map.
And, finally, don't wear shorts: Parisians consider them only vacation attire.