In this particular case, because criminals can hack Flock's databases. You can tell whether I'm leaving to go to work, coming home for lunch, figure out my patterns, and schedule a robbery. There are PLENTY of other reasons why I don't appreciate having a camera sitting at the end of my driveway, I wasn't notified about their decision nor had any input so it feels a bit intrusive, but surely you can appreciate that no system is 100% secure and that's why these persistent surveillance gear are so troubling.
This argument has been shot down so many times, it's a wonder anyone bothers to bring it up without googling it first.
So you would be okay with me personally tracking everything you do and recording you 24/7 then right? Because if you aren't doing anything wrong...
Because I'm not a criminal, so why should I put up with being treated like one?