Definitely a big big issue as the technology is becoming better and better everyday.
Other applications would involve finding the perpetrator of a crime through CCTV cameras in urban areas. Such scenario has all the ingredients of a new black mirror episode with a seemingly good idea turning terrible if in the wrong hands.
Maybe we should accept the fact that we live in a world where tragedies do happen and that we should not sacrifice our rights to privacy to prevent these.
To be honest from where I stand, here in Europe, I find it strange to see that a complete ban on guns (with the exception of security organisations) is the best way to minimize the rate of shooting incidents.
This is where it should start before bringing in human rights affecting solutions.
I was shocked to find that I needed my passport to exchange a small amount of local currency to USD. Is there anything that isn't tracked or monitored these days. Where does all this information go? The thought of it being used by bad actors has crossed my mind...