[Sir_Substance]

>if you do that you no longer get to claim that other "slippery slope arguments are fallacies".

You probably shouldn't be making that claim, to be honest. It's only a slippery slope fallacy if there's no historical evidence to support it. Part of the reason we record history is so we can tell whether a slippery slope might be a real danger.

There's several instances where a historical collection of information on citizens, done under claims to protect the people, turned into an oppressive regime, sometimes leading to the deaths of innocent citizens. The SS, Stasi and OVRA are all good examples, and a more current example can be found in China.