I think this form of medium latency low volume messaging is the only way to achieve true anonymity - it's too hard with interactive services and things sensitive to latency & jitter. Naturally, will likely not please Comey, but then, if they stopped the unprincipled mass surveillance, then maybe people would be less inclined to develop this stuff.
Assuming that he could find someone to explain it to him. Great research, look forward to something applied in the real world.