"We have hundreds of thousands of advertisers," said Google's Morrison told ABCNews.com in August. "We can't look at every ad, so we have to rely on automated methods."
He added, "It's an arms race. Every time we clamp down, they find a work around."
One of the largest online ad placement companies is Quigo, which is owned by AOL. The company places ads with ABC News, Fox News and USA Today, among others.
"AOL makes efforts to maintain high quality advertising standards," AOL said in an August written statement. "However, advertisers are ultimately responsible for complying with obligations concerning their consumers."
Legitimate Web sites continue to contract with ad placement firms despite the risk of scam ads because the revenue brought in by the ads is large compared to the minuscule financial cost of hosting the ads, said Eric Clemons, a professor at the Wharton School of Business at the University of Pennsylvania. The same isn't true, he said, for ads running on television and in newspapers, where commercial time and ad space, respectively, are more expensive.
"Basically, every little bit helps, and firms are not thinking about the reputational impact of accepting ads on a Web site that they would never accept either for print or broadcast," Clemons said.
Career expert Tory Johnson, the CEO of Women For Hire and a workplace contributor to "Good Morning America," says it is important for consumers to recognize the difference between news articles and ads placed on news sites.
Johnson has found links to apparent work-from-home scams on pages containing her own ABCNews.com articles.
"That's a key distinction," she said. "Consumers, Web site visitors should look for the fine print that says 'sponsored ads,' 'advertisement' or 'sponsored link.'"
The ads to suspicious work-from-home sites don't necessarily lead directly to the sites themselves. Often, the links lead to what appear to be newspaper sites. Such sites, the Better Business Bureau's Southwick said, are typically fake.
It's those phony newspaper sites that then link to work-from-home sites, including those that mislead consumers by using logos for Google and news organizations.
Kufel said that's how she wound up on the work-from-home site that ultimately scammed her -- she saw an advertisement for it on a news site, followed the ad link to what appeared to be a newspaper site and followed links from there to the work-from-home site.
After removing the company's charge from her credit card, Kufel was still worried that the company might try to charge her again, so she cancelled her card and asked that a credit reporting agency put a fraud alert on her credit report.
She also reached out to Meiselman, Denlea, Packman, Carton & Eberz, a New York law firm considering a class action lawsuit against companies perpetuating apparent work-from-home scams using the Google name.
Lawyer Jerome Noll said the companies have been hard to track down. He was not surprised to learn that Google's lawsuit targeted dozens of unnamed defendants in addition to Pacific WebWorks.
"If you try to hunt them down, they've got P.O. boxes, their phone numbers are disconnected," he said. "Unfortunately, there really isn't a defendant worth suing. ... They're fly-by-night operations that just are there to scam as many consumers as possible out of their money and then disappear."