Mobile computing giants in patent free-for-all

The mobile computing boom has turned into a courthouse war of the titans, as big tech companies are increasingly engaged in high-dollar legal disputes over lucrative patents for the software that makes smartphones and tablets so popular around the world.

Industry experts say they've never seen so many claims and counterclaims between major tech companies: Google threw a spotlight on the issue last week when it accused Apple, Microsoft and Oracle of using patents as weapons in an organized campaign to "strangle" Google's popular Android software. But other competitors, such as Nokia and Apple, have also feuded over patents in court.

"This is the biggest patent battle in U.S. history," said Joshua Walker of Lex Machina, an online tracking service that has counted a steady increase in disputes involving wireless phones and mobile computing. "There's no precedent for this."