You need to make sure the people in charge won't do that indefinitely. Even one particularly bad politician can cause some serious harm. If you limit their ability to monitor everyone, it limits their ability to round up dissenters. Given that surveillance doesn't seem to have much other use, it's reasonable to oppose it.

How can you limit their ability to monitor everyone, but not be able to limit their ability to round up dissenters?

If you discuss and regulate the privacy issues in times of peace it limits, or at least hinders, their ability to cause harm when they can take advantage of fear or rage.

I agree, but only when somewhat reasonable leaders get caught up in fear and rage. The issue of being or becoming a fascist state is rather different. I think there are excellent reasons to curb the surveillance state, I just don't see one of them being the avoidance of a totalitarian government.

Really? Weimar's human rights laws were second to none in the world for their time, and are considered exemplary even now. If what you say is true, how did the Nazi abuses occur?