According to a report, Facebook hired a public relations firm to launch a smear campaign against Google.

The report, from The Daily Beast, said it hired PR firm Burson-Marsteller to plant and pitch anti-Google stories in the media. The angle behind the anti-Google campaign was that the famous Mountain View, Calif. based search engine giant was invading people's privacies. Burson-Marsteller attempted to convince an influential blogger to post an op-ed about Google's privacy violations in The Washington Post, Politico, and The Huffington Post.

However, the blogger, Chris Soghoian, turned it down and then actuall published the emails. Following that, USA Today published a report saying two PR guys from Burson-Marsteller were pushing the anti-Google stories.  The emails and USA Today story opened up the case to speculation as to which company may have hired Burson-Masteller with Apple and Microsoft becoming possible candidates. In the end, it was reportedly facebook.

The Daily Beast said a Facebook PR person confirmed the company hired Burson-Marsteller to plant those stories. According to The Daily Beast, Facebook said Google is doing some things in social networking that raise privacy concerns. The concerns were mostly surrounding Google's Social Circle, which lets people find out information on their friends (and friends of friends) in a simple search setting. Facebook also did not like Google's attempts to use Facebook data in Social Circle.

Facebook, Google and Burson-Marsteller did not respond to inquiries for comment.

Until this incident, the Facebook-Google rivalry was lukewarm compared to other tech enemies (HP-Oracle, HP-Dell and Intel-Anyone In Semiconductors). The only notable interchange between the two companies was when Facebook hired a bunch of old Google executives, engineers and technicians. There were also rumors Google was building a social network to counter Facebook, but the only thing that ever amounted was its Buzz service.

The latest comments from Facebook are sure to put this up-and-coming rivalry to the forefront.

Follow Gabriel Perna on Twitter at @GabrielSPerna