They can just use Tor and HTTP upload. This protocol is more theoretical than practical. No protocol helps when you have to testify in court.

What makes you say this?

In Australia you can be sentenced for up to 5 years for refusing to testify (in a secret hearing you can't tell anyone about). 2 years for refusing to give encryption keys. In general one should not rely on a protocol to protect you if someone comes at you with a wrench.

> if someone comes at you with a wrench

relevant xkcd: https://xkcd.com/538/