NSA was spying on people for years before it was made public, tens of thousands of people had managed to keep their mouths shut. Collusion is a thing that happens all of the time, and considering the money involved its bound to happen again.
See also Mark Klein's denouncement of their AT&T spying, which prompted a lawsuit by the EFF back in 2006, charging them with having created an "illegal and unconstitutional program of dragnet communications surveillance".
There had been plenty of leaks over the years.