In March 2011, a company selling a popular series of guitar-lesson DVDs agreed to $250,000 to settle Federal Trade Commission charges that it deceptively advertised its products through online affiliate marketers who falsely posed as ordinary consumers or independent reviewers. According to the FTC release:
The Learn and Master Guitar program promoted by Legacy Learning and Smith is sold as a way to learn the guitar at home using DVDs and written materials. According to the FTC's complaint, Legacy Learning advertised using an online affiliate program, through which it recruited "Review Ad" affiliates to promote its courses through endorsements in articles, blog posts, and other online editorial material, with the endorsements appearing close to hyperlinks to Legacy's website. Affiliates received in exchange for substantial commissions on the sale of each product resulting from referrals. According to the FTC, such endorsements generated more than $5 million in sales of Legacy's courses.
"Whether they advertise directly or through affiliates, companies have an obligation to ensure that the advertising for their products is not deceptive," said David Vladeck, Director of the FTC's Bureau of Consumer Protection. "Advertisers using affiliate marketers to promote their products would be wise to put in place a reasonable monitoring program to verify that those affiliates follow the principles of truth in advertising."
In August 2010, a public relations agency hired by video game developers agreed to pay $250,000 to settle Federal
Trade Commission charges that it engaged in deceptive advertising by having
employees pose as ordinary consumers posting game reviews at the online iTunes
store, and not disclosing that the reviews came from paid employees working on
behalf of the developers. The company also agreed to set up a monitoring program to ensure compliance going forward.
Many aspects of social media provide great business opportunities, but it is important to ensure that your use, and your employee's use, of social media is done in way that does not create legal liability.

10 FAQs for the virtual world's layman
Overview of Legal Issues with Virtual Currencies
Virtual Worlds & Video Games Team