Google is packing its facial recognition and other tools into perhaps the smartest burglar alarm ever made. Home device maker nest – which is owned by Google's parent company, Alphabet – build upon the company's smart thermostat and smoke alarms in an attempt to revive the troubled brand. The company has been selling much the same products since it started six years ago, but has finally rolled out a new suite of security products intended to keep people's home safe. The central feature of the new alarm system is that it can recognise its owners but spot intruders, allowing it to smartly watch over the house. Although Nest has been among the early leaders in the effort to make home appliances as intelligent as people's smartphones, it hasn't been able to make money to the frustration of its corporate parent, Alphabet.