Take in account they'll look at fingerprints, sweat, DNA, type of paper, ink and type of printer used. Spelling errors, how you wrote something, etc can also be used to identify you. (Every printer leaves it's own watermark). Perhaps best to print and use a old 2nd hand xerox machine to copy everything or fax it from a public faxservice.

Write in foreign language you do not master well. All your errors are then "childish" and untraceable.

Or run it through Google translate (or equivilent) a few times and manually correct any critical words in the end result.

Hopefully it doesn't log the messages... or does it?

There are plenty of old typewriters lying around. Although you would still have to take precautions like getting rid of it afterwards and make sure it does not make use of polymer tape ribbons (in which case you would have to destroy and discard that as well).

Typewriters have signatures too: http://en.wikipedia.org/wiki/Typewriter#Forensic_examination

Sure, but the government wouldn't have a database of those anywhere and getting rid of a typewriter isn't likely to get anybody noticed (I cleaned up in the attick the other day, can you believe what I found?).

Good link, thanks.

Even better, receipt / thermal printers. No ribbon and pretty much untraceable. Lots of them lying around second hand in flea markets and yard sales.

Or maybe not that hard.

"Feds: Postal Service photographs every piece of mail it processes"

http://www.thesmokinggun.com/documents/woman-arrested-for-ob...

The bigger point is that journalists usually need to go back and forth with you.

Here is a good guide from Cryptome http://cryptome.org/cryptome-anon.htm

Tell the reporter to mail you at Mailinator or Lockbin.com and retrieve their messages by connecting with TOR.

Or tell the reporter to take out a classified ad in a free, public paper distributed in the nearest large metropolitan area.

The communications from the reporter don't need to be private or targeted. Everyone will know he's involved when he publishes, and he can reasonably encode questions by referring to the documents already sent. "MR X, CAN YOU PROVIDE FURTHER INFORMATION ON THE EVENTS DISCUSSED ON PAGE 13."

The communications from the journalist certainly do need to be private. Advertising that you are working on a story that will reveal big government secrets is a good way to be put under surveillance to find out who is doing the leaking to you. The journalist would not want to announce to the world that the process of receiving classified information is ongoing.

The ad can be written so as to look innocuous to anyone other than the journalist and the leaker, if those two can agree on a format for doing so.