This sounds to me like journalistic license from Greenwald, who probably does not fully understand the technology involved. I'm guessing it's a little more nuan

This sounds to me like journalistic license from Greenwald, who probably does not fully understand the technology involved. I'm guessing it's a little more nuanced: one could learn about known exploits and compromised services to stay on "safe" communication methods, or use some of the exploits themselves.