Companies that deal in shady free gift card offers have managed to game Google's sponsored search results so they can pass themselves off as representing the official sites of such huge brands as Walmart, Best Buy, McDonald's and Hooters, among others, PCWorld has found.Google shut down the accounts responsible for the deception when PCWorld approached the search giant this week. Google representatives wouldn't disclose how they were tricked into accepting the ads, which violate their guidelines. But a source within the advertising industry familiar with this type of scheme said he suspects that the rogue company or companies involved knew the Internet Protocol addresses used by the Google employees charged with checking the validity of new ads. (The source asked not to be identified to protect his position in the industry.) Using that information, the company could show Google employees one site, while anyone from the general public who clicked the sponsored link would go to a different page.The failure of Google to detect the bogus ads should disturb consumers, says online marketing expert Ben Edelman, an assistant professor at Harvard Business School. "These ads are clearly attempting to deceive the consumer into thinking the offers are from Best Buy or whatever the brand," Edelman says. "A free gift card scam is innocuous relative to the harm that could be done by spoofing a financial institution." But, Edelman says, "If Best Buy can be spoofed, why can't Bank of America?"Google spokesperson Jim Prosser says that several advertisers' accounts had immediately been shut down as a result of PCWorld's inquiries. "We have engineering teams and systems that work to proactively prevent violations of our advertising policies, and we work quickly to review, suspend, or remove ads when we are notified of potential violations," Prosser says. "That's what we've done with the accounts you've mentioned. We also take strong action to inform authorities, and have taken legal action ourselves against scams that attempt to trick users."PCWorld attempted to contact the companies listed on the gift card offers that we found over the course of this investigation. The companies listed on the ads were Better-Gifts.net, DirectSurveySolutions.com, Tester-Rewards.com, eSolutionsMedia.net, FoodCritic101.com, I-Deal Direct, and Top Notch Media.Only Top Notch Media--which was tied to free gift card offers associated with bogus Google ads for the brands Hooters, Ikea, and Whole Foods Market--replied to our inquiries. The company's e-mail response states: "We have identified this traffic partner and subsequently terminated this traffic source to all of our Topnotch-media.com websites. Please note this ad placement is in violation of our traffic agreement and we do not want traffic generated in this manner." The company did not identify the "traffic partner" involved.Why are free gift card offers a danger to Web consumers? Because they're often used to convince people to give out valuable personal information--data that they sell to marketers who use it to inundate the unlucky consumers with targeted advertising. In many cases, the consumers never receive the gift card that they thought they were in line for. If the offers come from large brands that people trust, individuals are likely to be more inclined to participate.Google specifically bans free gift card offers from sponsored search ads, Prosser says. The Better Business Bureau has warned consumers about them, and Walmart tells its customers that such offers are a "scam."Deceptive LinksThe gift card deception took advantage of a common practice by big retailers. The marketing companies know that many Web users who don't know the exact address of a company's Website will search for it in Google, using the company's name as the search term. To ensure that searchers find their main site, reputable companies like Walmart or Best Buy may pay Google to have a sponsored link to their site appear at the top of search results for their name.For instance, Visa purchased the top Sponsored Link when you run a search for "Visa" on Google, delivering an ad that reads "Visa Official Site." Clicking the ad takes you to Visa's corporate home on the Internet.But this past week, similar queries on Google's search engine for major brands delivered sponsored ads that claimed to link to official big-brand sites, but in fact led to sites that had no connection to the brands listed. For example, when I searched for "Best Buy" on Google from Boston on Monday, the top sponsored ad accompanying the search results was headed "Best Buy Official Site" and displayed its URL as "www.BestBuy.com"; but when I clicked the ad,I was taken to a site called Tester-Rewards.com, which used the Best Buy logo to promote a "free" $1000 Best Buy gift card promotion not authorized by Best Buy.Search results varied depending on where the person submitting the search request was located. PCWorld spotted bogus Google Sponsored Link ads through searches in a number of different East Coast cities. Identical searches undertaken in other parts of the United States didn't deliver the same results. Advertisers can target sponsored links shown in Google search results to certain areas of the country or the world.Best Buy says that Tester-Rewards.com is not affiliated with it in any way. Tester-Rewards.com did not reply to repeated requests for comment for this story. In the fine print below the Best Buy offer, Tester-Rewards.com offers this disclaimer: "Tester-Rewards.com is not affiliated with Best Buy..."Clearly the ads would not have been allowed if Google had understood how they operated. Prosser says that it's impermissible for a Google AdSense ad to claim to be the link to an official company Website and then deliver you to an unrelated site.(Click the image below of a bogus Walmart Official Site ad to see the gift card page that it led to.)Many Brands InvolvedPCWorld found that the deceptive marketers have targeted a large number of big-name brands--including Bed Bath & Beyond, Best Buy, Hooters, Ikea, Martha Stewart,McDonald's, Petco, Walmart, and Whole Foods Market--for this type of misleading advertising on Google within the past week. (Click the image below to see a full-screen version of the fake McDonald's ad.)In most cases, searching Google for various specific brands from computers located on the East Coast yielded top Google Sponsored Links claiming to take the searcher to the brands' official Website. The exception was the unauthorized ad for Ikea; the ad did not purport to be for the company's "Official Site." It merely posted the word "Ikea" and the URL "www.Ikea.com" along with the phrase "Beautiful solutions for your house visit us today."When notified of the spurious ads by PCWorld, Google immediately shut them down.Dealing with people who misrepresent themselves is an issue that everyone on the Internet lives with, according to Prosser. The Google AdSense team works hard to vet ads before the public sees them, Prosser says, adding that each ad must live up to strict standards: "Ads must be relevant, original, high quality, and can't be misleading. If a site is deemed [to have] a low quality landing page [the Web page the site takes you to when you click on it] we will disable the ad."Get Your Free $500 Gift CardPeople in the advertising industry refer to free gift card offers as incentive marketing--a growing and lucrative part of the advertising business, in which marketers promise something of value in return for personal information about the gift card recipient. The bargain is sometimes the promise of free iPods and gift cards. The marketer then sells profiles of the recipient's personal data to other advertisers, who pitch offers to targeted demographics. "There is a sliding scale of black, gray, and legitimate ways to do this type of marketing," says Peter Bordes, chief executive officer of MediaTrust, an online advertising firm. Free gift card offers are one of the crudest ways to entice people to hand over personal information, he says.A bogus Ikea gift card offer on Facebook took in 40,000 victims earlier this year. Facebook promised action against the fake gift card offers this past April.The site (maintained by Tester-Rewards) that offers an opportunity to receive a Best Buy gift cards reads: "Congratulations! Get a $1000 gift card free!" To become eligible for the $1000 Best Buy gift card, you must share personally identifying information, including your phone number. According to the site's terms of service, registering with the site is the same as "expressly requesting a phone call, pre-recorded message, SMS text (std msg rates may apply) and\/or email from this list of Marketing Partners: WCA, NationalCashFinder, Debt Reduction Experts, YourDiabeticSavings, MyEducationAdvisors or Automobile Protection Plus."Offers for free gift cards have been the bane of both consumers and the companies whose brands are used lure consumers. Walmart has set up an informational page called "Gift Card Sponsor Scam," warning people against the marketing tactic. The Better Business Bureau has notified consumers of shady gift card offers, too.Walmart warns: "The goal of this scam is to encourage consumers to spend money on 'sponsor offers' in the belief that they will eventually receive a high value gift card. However, after fulfilling the 'sponsor offers' the consumer may never even receive the gift card or will have spent more money on the offers than the worth of the gift card."Protecting Yourself From Bogus AdsUsing advertisements to make services look legitimate is nothing new, says Paula Greve, director of Web security research at McAfee. "They have been used to drive traffic to free product and gift card offers, malware-laced Web pages, and phishing scams," Greve says. She says that McAfee has noticed more attempts at fraud within search engine ads because it's getting harder to manipulate natural search results to make shady pitches rise to the top of results.What's unique in this instance, she says, is the fact that shady marketers were able to pass themselves off as official Web sites of large brands in Google Sponsored Links. Usually, questionable ads refer to brands, but stop short of claiming to be those brand.Many people use tools like McAfee's free SiteAdvisor utility to alert them to suspicious links in search results. SiteAdvisor flags sites with red, yellow, or green markings, with red indicating the most dangerous sites.But SiteAdvisor wouldn't have helped searchers avoid these bogus links. Greve says that Google Sponsored Links aren't scanned for safety. But while the tool won't warn you before you click such a link, it will warn you once you arrive at a questionable site.Online advertising expert Edelman of Harvard Business School says that Web users should be able to depend on Google for better protection. "Google should be checking ads more vigorously to prevent this type of scam," he says. "This doesn't seem to be a particularly sophisticated scam. Google owes it to its users to be a little bit smarter than the dubious marketers."