It's really not that easy to monitor for every possible violation/exfiltration, especially at that scale. Of course those need to be monitored for, but they're

It's really not that easy to monitor for every possible violation/exfiltration, especially at that scale. Of course those need to be monitored for, but they're never perfect. NSA obviously had mechanisms to detect this, but it didn't work for Snowden. They likely have already had such monitoring in place for years, and are probably augmenting it now. It just didn't work.