What about writing a letter, with pictures and everything, and sending it to a bunch of people who then scan it with or without OCR and then post it online? There could even be a group of such people that, as a kind of public service, agree to do this. They could, for example, burn the original.
You don't burn anything, you hope your recipients are diligent and follow up on their promises. Making this one of the less safe ways to get out data, because it's not self-reliant.
Actually, I meant that the recipient burns the letter after transcription. That protects the sender in case someone comes snooping after the sender and tries to hit up the recipient for more details.
Regarding self-reliance: theoretically, there is no self-reliant way to "get data out". Every method requires at least the involvement of the recipient. This sounds pedantic but it's a serious point. If you really don't want to rely on anyone, why are you bothering sending people messages anyway?
If the message is persistent, then some lasting mark on the world has to be made - and there will always be a non-zero chance that that mark can be associated with you.
Methods requiring computers require an unusually large amount of reliance on others, actually. You rely on the hardware and software one is using, up to and including all of the infrastructure between you and your recipients. Computers are fundamentally microscopic phenomena, and yet controlled by other humans: how do you know that your hardware and software is doing what you think it's doing? Without an electron microscope and a great deal of time, you cant. (And even then, the microscope is subject to manipulation, so you can't be fully certain).
There's another problem with persistent distribution of anonymous data, which is the denial of service attack. An entity wishing to stop another from speaking can either stop the speech, or they have the option to parrot the speech, but altered enough to constitute noise, and weaken the opponents position, generally confuse the issue. No system is going to prevent a noise counter-measure, since presumably the system is available for anyone for anything.
