The Constitution is not a suicide pact
One way or the other, law enforcement must have total access to all of terrorist's writings, and certainly, whether "tech giants" like it or not, digital content can't be considered in a different manner than content on paper. The digital revolution has had a profound, irreversible and chilling effect on privacy, and I don't see why terrorists should be afforded more protection than anyone else. Eventually, once the present paralysis of government is ended, amendment(s) to the Constitution will be considered. The one thing that Nobody is addressing is that when government is using extraordinary power to search for evidence of terrorism, what can they be allowed to do when they come across evidence of more prosaic misdeeds.