"dragnet surveillance laws"
The problem lies right in the title : dragnet.
No fine-tuning, no discrimination, just violate everyone's privacy and hope you find something. After all, you're The Law. The good guy. Except when you abuse your powers to check on your wife, which is sooo easy to do. Just rewatch True Lies.
I would like, nay, I demand, a report on how many times this global violation of privacy has resulted in stopping crime, let alone terrorism.
If you could prove, without doubt, that raping my privacy has stopped significantly more criminals than you could have without it, then I might rethink my attitude on that.
But you won't, because you cannot actually justify any concrete benefit.