My question to everyone supporting restrictions on speech and supporting privacy violations, even for good reasons, is this: are you prepared to have these tools fall into the wrong hands? The same methods used to quickly shut down a dangerous website or to track down a terrorist by their online posts can be used to silence protests and to hunt down political opposition.
Yes, because society has a plurality of institutions that constrain power. Restrictions (even speech restrictions themselves) are subject to the court of public opinion (we're talking about them right now), there's the judiciary, political opposition and so on.
This argument never had any pull for me for the same reason I'm against abolishing the police or abolishing surveillance or anything else. Power, even in the hands of people I don't like, can't be exercised arbitrarily.