Even if we ignore privacy and effectiveness, the problem with authoritarian methods is that they can (and most likely will) be abused. The justification may be

Even if we ignore privacy and effectiveness, the problem with authoritarian methods is that they can (and most likely will) be abused. The justification may be to catch predators and terrorists (which is uncomfortable to argue against lest you be labeled a predator / terrorist sympathizer yourself), but it will in practice be used to surveil political rivals, journalists, activists etc.