Facebook counter sues Yahoo in escalating patent war

Facebook is counter suing Yahoo in an escalating patent battle between the rival internet firms.

Facebook claims Yahoo violated its patents covering photo tagging, advertising and online recommendations, according to the BBC.

The counter lawsuit indicates that, although Facebook has relatively few patents, the social networking firm believes it has been able to file or buy enough intellectual property to retaliate against an attack from a more established player such as Yahoo, according to the Financial Times.

Last month, Yahoo sued Facebook, accusing it of infringing 10 of Yahoo's patents, including systems and methods for advertising on the web.

The beleaguered internet company alleges Facebook's entire social networking model is based on Yahoo's patented social networking technology.

The case echoes Yahoo's decision to sue Google ahead of its public listing in 2004. Yahoo sued Google over patents acquired the previous year through its takeover of pay-per-position specialist Overture. Google settled the case by issuing 2.7 million shares to Yahoo.

Analysts have said the attack on Facebook may be an attempt by Yahoo to use a tactic that has worked before to boost the company's finances after consecutive quarters of declining revenues.

Facebook, which held just 56 patents at the end of 2011, recently acquired 750 patents from IBM. But Facebook still trails behind Yahoo, which owns about 1,000 patents.

Industry pundits say these cases could spend years in litigation and a settlement is often reached where the parties simply agree to license the patents to each other.