A little searching will find you all sorts of such hits, like an officer tracking her domestic partner [0], an officer stalking someone after meeting on a TV set* [1], another officer tracking his ex partner [2], another officer tracking his mistress [3]. This is just a random sample.
* Note this scenario was not with Flock, which is important: there's more than one player in this space. Kill Flock and others might roll in; something broader is needed like, oh, I don't know, constitutional protections or something.
I wouldn't be surprised to find that the quality of the average cop in the US has improved since the 1960s, at least by some measures. But they are a lot more heavily armed, so mistakes and malfeasance on their part is deadlier.
The big thing that's changed is that you're hearing about it. The second biggest thing is that we've given cops more and more access to automated systems that they can misuse.