According to the security firm Sophos, most “likes” on Facebook corporate pages such as Ford, GM, Krispy Kreme and others could be fraudulent.

"Spammers and malware authors can mass produce false Facebook profiles to help them spread dangerous links and spam, and trick people into befriending them" Sophos' Graham Cluley told the BBC.

According to Cluley, most suspect accounts are usually run by a single person operating thousands of profiles via specialized computer software. Most of the fake accounts appear to come from the Middle East and the Pacific Rim.

For corporations, the revelation that most of their social media fans don't exist may mean a redesign of their social media strategy with more sophisticated media analytics.  For government agencies like the U.S. Department of State and Defense--the notion  the citizens they serve may also be fake poses a problem for agencies that measure success based on only Facebook.

Ironically, both corporations and federal agencies pay marketing organizations hundreds of thousands of dollars for micro-targeted campaigns aimed at specific demographics spawning a cottage industry in print publishing and research social media to reach out to potential customers and citizens.  But  today's revelation implies there are additional caveats compounding the value of social media as a media tool or investment.

"Any kind of investment in Facebook advertising has brought us very little in sales," The executive--who spoke on background with the BBC's Rory Cellan-Jones, said. "the fans you get from advertising may not be genuine, and if they are genuine are they people who will engage with your brand?"

For its part, the Facebook claims only 5-6% of its user base--or 54 million users--could be fake. Yet with companies like GM abandoning Facebook, corporations may need to rethink using social-media-as-branding-tool.