Each drone, the company says, is programmed to remain a constant distance from whatever it's following, either a person or a car, for safety reasons. If communications with the drone are interrupted, it automatically lands in a safe place to avoid damaging itself.
since crime of any sort in Japan - includng break-ins - is relatively rare. Japanese companies can rent the drone as part of Secom's online security system for around 5,000 yen ($58) a month some time after April 2014, though a company spokesperson said Secom wants to expand that to other countries eventually.
via AFP, Secom (in Japanese)