A slide to unlock feature is fairly commonplace feature across most Android handsets. As of yesterday morning however, the United States Patent & Trademark Office has confirmed it as an invention of Apple.
Those Android manufacturers who employ the feature in their smartphones are now at risk of a hefty patent infringement lawsuit unless a court rules it is invalid or prior art. Apple originally filed for the patent in 2005, although it won a similar patent in 2010 which focused on lock screen animations.
It remains to be seen how the iPhone-makers will utilise their new piece of legal ammunition yet it would be surprising if was left sitting in limbo for long.
On a side note, in the video below you see the 2004-5 Neonode N1m, a phone which existed before the iPhone, employing an extremely similar feature to Slide to Unlock. A Dutch court had previously ruled that the Slide to Unlock patent was invalid because of this device.