Sunflower Labs, a San Francisco-based startup, is combining motion detectors, a quadcopter and a phone app into a home security system. The Sunflower system could go on sale in 2020, according to CEO Alex Pachikov, who expects to charge wealthy customers several hundred dollars a month for the peace of mind -- and replacement hardware if anything breaks. For comparison, premium security systems can cost more than $100 a month, and Sunflower says that six-camera systems can cost up to $300 per month.