Although I like SDF, a physical letter is a lot more evidence and perhaps hassle than what you'd incur with Tor and some boring free shared hosting service, or

Although I like SDF, a physical letter is a lot more evidence and perhaps hassle than what you'd incur with Tor and some boring free shared hosting service, or running a Tor hidden service if you want interactivity and don't mind slowness, or even joining a Bitcoin mining pool and using the (minimal) payout to anonymously pay for hosting.