Arizona realtor surprised to find Canadian "white hat" hacker talking to him through his smart doorbell

Arizona realtor Andy Gregg's Nest doorbell/camera started talking to him: the voice on the other end identified itself as a Canadian "white hat" security researcher who'd broken into his camera by using a password that Gregg had used on multiple services, including some that had been breached. The hacker warned him that he was vulnerable and told him to tighten up his security before a bad guy got into his doorbell.