The validity of has been questioned in numerous patent cases, with Apple of the Samsung Galaxy Tab in Australia, from at least five Android vendors, and over use of Java.

Still another example led Google chief legal officer David Drummond to accuse rivals of teaming up against Android. Drummond called out for $4.5 billion, beating out a $900 million bid from Google.

In a post on Google's official blog titled "," Drummond bemoans that Google's rivals bought Nortel patents "to make sure Google didn't get them," while "seeking $15 licensing fees for every Android device; attempting to make it more expensive for phone manufacturers to license Android (which we provide free of charge) than Mobile; and even suing Barnes & Noble, HTC, Motorola, and Samsung. Patents were meant to encourage innovation, but lately they are being used as a weapon to stop it."

Drummond promised that Google is "looking at other ways to reduce the anti-competitive threats against Android by strengthening our own patent portfolio," while warning that continued patent problems will force consumers to pay more for Android devices.