If memory serves me, the owner/writer of CARNIVORE died suddenly by a suicide, but the details don’t support the findings. He didn’t want to give the government complete control of his software.
I heard that once, too, but don’t know anything about it. I know a certain not-to-be-named messaging system was developed and the dev team felt very uneasy about it all so they left that world and scattered. Carnivore was a simplistic system that didn’t utilize the techniques now in place, specifically software that runs on primary pipes. It relied on a storage mechanism to capture specific data while today’s systems simple capture anything and everything in real-time and sends it on.