[dragonwriter]

> How come criminals didn't ... ahem ... invest in their own communication platform?

They did.

The thing with criminals is that that they have a built-in pressure point against which law enforcement can apply leverage, so when your platform for criminal communication is owned by other criminals, you risk the criminal platform operator being flipped against the criminal platform users, with the platform then being covertly owned by law enforcement.

Now, you may ask, why didn't each criminal network invest in developing the capacity for its own covert communication platform. And that's a good question, but I’m going to suggest that an important use case of covert communication systems i orgabized crime is communication between criminal organizations that have loose and shifting connections.