by Russell Brandom of www.theverge.com
AdWords is the core of the
business of Google, delivering billions of data-targeted ads to browsers
every year. Most of the ads are legitimate, but not all of them, and
it’s Google’s job to tell which is which. Last year, that meant kicking
224 million ads off the network. The majority were run-of-the-mill web
fraud: counterfeit handbags, thinly veiled phishing schemes, the kind of
thing any decent spam filter would take out. But in 2010, in the midst
of reworking the ad-filtering model, something strange happened. The new
model was flagging a lot of otherwise innocuous ads for used cars. Most
of the bad products were counterfeit goods, and, as AdWords engineering
director David Baker says, "We'd never heard of a counterfeit car." Had
they trained AdWords into anti-car prejudice? Was the model simply
broken?
Had they trained AdWords into anti-car prejudice?
The answer turned out to be
even stranger. They were real cars, but they weren't really for sale.
Scammers were taking pictures of cars on the street, and when a hapless
customer showed up a few days later offering money, they'd steal the car
and hand it over. By the time the mark realized he had purchased stolen
goods, the sellers were long gone, taking his money with them. It's a
lucrative scam, and in China, a well-known one — but to anyone looking
at the ads, it just looks like one more crop of used-car ads.
For those who study fraud in
China, on the other hand, this is far from surprising. "These people are
very professional," says Dahui Li, an information systems expert at the
University of Minnesota who specializes in Chinese online fraud. In the
case of the car scam, he says the offline component is the most
important part, as a way to assure skeptical customers that the sale is
legit. "Chinese people want to see the product before they pay for it,"
Li says. "They have to see the car." So the criminal element developed a
scheme that could show it to them.
"They have to see the car."
According to Li, the larger
problem is the Chinese financial system, which requires every
bank-to-bank transaction to be routed through the central government’s
banking authority. As a result, anti-fraud measures are usually slower
than criminals. Stopping a payment could take as long as three days, by
which time the money is usually unrecoverable. Since customers can't
trust the banks to stop fraud, they're left to fend for themselves. On
Taobao, the Chinese equivalent of eBay, Li sees this effect driving
customers to have longer conversations before they trust a seller,
testing out every offer to make sure it's legitimate. In other markets,
it boils down to common-sense habits like holding the product in your
hands before you buy it. And as the sales move offline, so does the
fraud. Li describes scams that create fake websites, designed to fool
users into thinking they’re on Taobao or another moderated e-commerce
site. Even when police are able to follow the credit card trail,
criminals are able to stay a few steps ahead. "Until the payment model
is fixed, you’re always going to see these scams," Li says.
"Until the payment model is fixed, you're always going to see these scams."
The surprising thing is how
much this supposedly offline fraud caught the attention of Google’s
AdWords cops. The team is only looking for fraudulent offers made on the
AdWords network, but scams like the car-swapping trick blur the lines
between the crimes that happen on the network and the crimes that take
place after the fact. More importantly, AdWords’ crime-spotting tools
don’t distinguish between online and offline scams. They’re just looking
for suspicious behavior. Like many Google products, AdWords' quality
control is managed by a massive machine-learning algorithm, similar to
the PageRank function that powers Google Search. "There’s no one thing
or even a handful of things," says Baker. "It’s thousands of pieces of
information in aggregate." That includes IP address, account age, and
links to past accounts. After millions of iterations, it’s hard to trace
the red flags back to any group of factors, which makes it even harder
for bad guys to game the system.
Cultural differences could fool the humans, but they couldn't fool the machine
More importantly, it doesn’t
take human prejudice into account. Baker and his team weren’t looking
for cars or car thieves. But the algorithm saw a pattern of quick buys
from new accounts, tied together with larger and more subtle patterns,
and deduced something was up. It’s not an airtight system: more than a
few valid accounts have had their orders delayed while the team checked
them out. But in this case, it was able to reach across continents to
suss out a scheme its engineers had never even imagined. Cultural
differences could fool the humans, but they couldn’t fool the machine.
At the same time, once Google
found the scammers, they couldn’t do any more than kick them off
AdWords. Baker and his team will occasionally forward ads on to law
enforcement, particularly if drugs are involved, but the relationship
between Google and China is so complex that scams like this car theft
ring usually slip through the cracks. It makes sense; Google isn’t in
the crime-fighting business. But as they try to keep scams from spilling
onto their network, they’re getting awfully close.
Source (via www.autoblog.com);
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