If I am observing an object such as a forum thread, it is then trivial to make use of commonly available heuristic data as a ciphered communication channel.

Example A:

User X© makes a post with subject including trigger word

Bot Y¥ sees the trigger then validates a confirmation trigger within the body of the post. (formatting sequence such as X/num punctuation marks depending on numerolology of OP's username)

Example B:

Observed subject edits post multiple times. Each edit, when applied to a crystallographic chart vis avis a pre-determined schedule result in plaintext.

Eg: User edits 'who' into 'how' on the subsequent GMT date and the cipher provides a simple '-w +h [pos grid ASCII MSG]*SHIFT(datediff) '

And you have a plaintext message.

It isn't my fault the message is a keyphrase to open Goatse. I warned y'all before I was honeypot alpha, yet you gave me all your tools and secrets anyway...