Surveillance enables many kinds of government oppression, but large-scale ethnic cleansing doesn't seem to be one of them, in that it's already possible and efficient. The Nazi's logistical problems in enacting the Holocaust were more in moving and killing Jews, less in finding them.
ETA: many of the Dutch Jews who did survive were hidden by Dutch people. And yes, such efforts could be thwarted by surveillance. But that seems like an edge case; rare even in the Netherlands, where only a few percent of local Jews were so hidden, and vanishingly rare in the Holocaust as a whole across Europe.
If they had there would most likely not be a Jewish people to speak of, as it was the little bit of automation they had coupled with a stereotypical dose of German thorougness already did a very good job (good is not really applicable here). Now combine that with say a twist of 'big data' and some nice pattern recognition algorithms (facial recognition for instance, or maybe DNA analysis) and it would have been possible to round up a significantly larger chunk of the Jewish population than what already happened.
The fact that we now have wall penetrating radar doesn't help either.
> The Nazi's logistical problems in enacting the Holocaust were more in moving and killing Jews, less in finding them.
They had a hard time actually, because the local population did a reasonably good job of hiding them in the strangest spots.
> Surveillance enables many kinds of government oppression, but large-scale ethnic cleansing doesn't seem to be one of them, in that it's already possible and efficient.
Yes. But it won't be made any less efficient by all this helpful identification technology we have nowadays, most likely more, and communications intercepted long before a conflict might even help to identify those that would aid the hunted.
There was significant custom logistical technology developed for the challenge of tracking millions of people during the Holocaust.
Interestingly though, just after the wall fell if there was one country that was hyper-sensitive to any kind of surveillance it was the Eastern part of re-united Germany. That was one part of Europe where people seemed to 'get it' in large enough numbers to actually make a difference. Some parts of Poland after their independence from Soviet domination as well.
Though for the most part that seems to have slowly crumbled away.
A couple of razzias where they or their loved ones were taken to gas chambers should do the job.
But we have such short memories.
In just about every Dutch town, usually near the railway station there is a monument documenting just that and it still does not seem to make much of a difference.