Then again, back in old timey times, wiretaps were made of actual wire, which depends on an insecurity in the very laws of physics. And then, as now, it was frequently abused - a friend of a friend actually lost his job for wiretapping his ex-wife.
So we already have rules and customs to deal with this. They're imperfect, they rely on human enforcement, and all the problems associated with rules. But they've worked fairly well mostly, and that may be as good as it gets.