I always cringe when people say this ignorance.

Yes! Yes they very much can and sometimes do. For everything you do on a daily basis, I can assure you there is some law that they can use on you, if they really wanted to make the effort. There are hundreds of these laws on the books that are dirty and many outright unconstitutional.
And no, I am not going to post links. Do the research because there are WAY to many examples and information about it out there. And no, not from internet chat rooms but from law universities and legal aids.

And maybe you don't mind the audio file of you & your wife screwing in the bedroom, being listen to by dozens of 3rd party contractors that they share that with.
Or video of your kids outside playing in the yard, showing up on child porn sites with deranged people wacking off to it.

Is there always someone home? Some criminals could find out what homes are empty during the day and easy targets without putting much effort into it. Meaning more try it. An alert on your phone isn't going to stop a snatch & grab, when they know no one is there to stop them. Or maybe they get bold because they think no one is home and after breaking in, find someone is? How is that going to turn out - statistically not well for the victims.

Going to arm yourself in your home? Well, the police already know you are armed then. Removes that doubt that someone was armed and possibly dangerous when they do that welfare check. "Police have investigated themselves and found no fault for the shooting of the entire family".

Do we really want to go down this deep rabbit hole of how negatively ultimate surveillance can screw you, if you don't give a crap about your own privacy?