BBB: Beware of Facebook Ads

Logging onto Facebook usually brings up advertisements, on everything from weight loss tricks to teeth whitening products, alongside notes and updates from friends. But now the Better Business Bureau is warning that some of those advertisements can get Facebook users into trouble.

The problem, says Steve Cox, the bureau's spokesman, is that some of the ads link to questionable consumer testimonies or blogs that appear to endorse products. Among the most notable: Ads selling acai berry supplements that promise to help consumers lose weight. Some acai ads link to fake blogs that pretend to be created by real users, but are really just advertisements. Those blogs also connect customers to sales pages that promise free trials, but can end up charging them almost $90 a month if they forget to cancel quickly. BBB says it has received thousands of complaints over billing problems from acai supplement companies.

The bureau has also received thousands of complaints about advertisements offering hefty salaries, as much as $67,000 a year, to stay-at-home moms. Like the acai ads, many of these link to fake blogs, purportedly written by people who are making a lot of money by creating websites that host Google ads. Also like the acai ads, the blogs link to web sites offering free trials that can end up charging customers $70 a month if they don't cancel quickly. BBB warns that even though the ads use the word "Google" and Google's logo, they are not affiliated with the company.

The bottom line: As on all websites, watch out for shady advertisements on social networking sites. And be suspicious of blogs offering hearty product endorsements.

• Fake blogs also help fuel another scam -- selling information about how to win government grants. Read more: "Recession Scams Prey on Desperate Consumers."