Tragically, given the mass atrocities perpetrated throughout human history, it's inevitable that records of who people are, their race, ethnicity, religion, political affiliation, sexual orientation, and/or other data about them (which is now collected and distributed at a larger scale than at any time in human history) will be used to commit more mass atrocities.

We are living on borrowed time.

Whereas before some people could escape detection or escape being rounded up, the next time the slaughter will be much more effective.

Also, in the past it was much harder to detect people who didn't stand out in some obvious way (through skin color, mode of dress, or obvious behavior), now there are records of people's interests and communications which make them much easier to target.

That did not exist before except through a relatively primitive network of informants, or unless the people outed themselves through publishing their writing.

Not to mention how much more advanced tracking technology is these days, and how much harder it is to hide.

All of this put together makes the current surveillance aparatus infinitely more sophisticated and powerful than it was throughout almost all of the 20th Century.

It really is just a matter of time until it gets used by people with an agenda and/or a grudge against some victim group(s). Saying it hasn't happened yet so it won't is just wishful thinking.

When the have the cooperation and participation of the military, the secret police, and the general population (as has often been the case in many atrocities, genocides, and pogroms in the past) it's even worse, and by the time the video evidence gets out (if it ever does) it's too late to save the victims, assuming there's even anyone in the position to do so.

"Mass atrocities" are difficult to carry out, and conceal, for very long.