Just an FYI, certain followers of You-Know-Who, captured and detained in Azkaban, have been given special journals by one of the Auror teams. The idea is that hopefully other Death Eaters may contact them and any information obtained via the journal can be used to track down the remaining few who escaped. They don't have wands, and cannot hex. Anything hexed to them will be readable by Aurors who periodically check the journals for clues and replies.
The DEs must remain civil and cordial to members of the public they are capable of communicating with, or else lose all privilege the journal offers.
Ok. Which explains how Rabastan can post, by the way :)