But just a zero day in Tails wouldn’t be enough to get Snowden. It would maybe let them get into his accounts, which we would have no idea about unless someone told us, but to silence him, they’d need to delete the files or find where he was. For whatever reason, they are unable to kill him while he’s in Russia, and I doubt Snowden keeps the only copy of the files hooked up to his computer while he’s online. You can do all your work offline, and only go online while sending something.
(I think they haven’t gone and killed Snowden yet because Russia would respond with World War 3. The probability of Russia doing that is high enough to justify inaction. Or in other words, the NSA knows how to lose.)
Snowden is sort of a special case here, as he uses Tails, which has very low adoption, and the value of an exploit is not as large as the value of an exploit in Windows. That said, there have been exploits in Tails:https://www.schneier.com/blog/archives/2014/07/security_vulner_4.html http://www.forbes.com/sites/thomasbrewster/2014/07/21/exploit-dealer-snowdens-favourite-os-tails-has-zero-day-vulnerabilities-lurking-inside/. NSA could probably find one for a few million (consider that a wild guess).
But just a zero day in Tails wouldn’t be enough to get Snowden. It would maybe let them get into his accounts, which we would have no idea about unless someone told us, but to silence him, they’d need to delete the files or find where he was. For whatever reason, they are unable to kill him while he’s in Russia, and I doubt Snowden keeps the only copy of the files hooked up to his computer while he’s online. You can do all your work offline, and only go online while sending something.
(I think they haven’t gone and killed Snowden yet because Russia would respond with World War 3. The probability of Russia doing that is high enough to justify inaction. Or in other words, the NSA knows how to lose.)