Apple has been granted a patent that could spell trouble for Google and Android handset makers the world over.

Patent number 8,046,721, granted yesterday by the US Patent and Trademarks Office (USTPO) has been assigned to Apple and effectively gives Cupertino the rights to the 'slide to unlock' gesture.

"A device with a touch-sensitive display may be unlocked via gestures performed on the touch-sensitive display. The device is unlocked if contact with the display corresponds to a predefined gesture for unlocking the device. The device displays one or more unlock images with respect to which the predefined gesture is to be performed in order to unlock the device," the patent's absract reads.

"The performance of the predefined gesture with respect to the unlock image may include moving the unlock image to a predefined location and/or moving the unlock image along a predefined path. The device may also display visual cues of the predefined gesture on the touch screen to remind a user of the gesture," it continues.

It would appear, then, that every Android handset and tablet is using technology now patented by Apple. Given Steve Jobs' reported vows to go 'thermonuclear' on Android, we could be in for another round of major legal battles involving Apple and Android handset makers, as we've seen with Samsung and HTC in recent months.

However, this could also be a pre-cursor for the first direct battle between Apple and Google over Android. We'll have to wait and see.