When someone suggests rolling their own crypto a bunch of people pop up to point out the considerable risks.<p>We need the same for these &quot;wheat &#x2F; chaff&quot; steganographic noise generation schemes. Steganography is probably secure, but people tend to vastly underestimate the amount of cover material needed.<p>Considerable money and time has been devoted to &quot;finding the real signal&quot;.<p>The Usenet keyword triggers were trivially easy to filter.  Mostly because people just put a list, in all caps, at the end of their post.<p>We know these are trivially easy to filter because putting a list like [ECHELON CIA NSA GCHQ IRA BOMB inurl:groups.google.com] returns loads.  Here&#x27;s one example, with the handy words &quot;anti echelon block&quot; <a href="https:&#x2F;&#x2F;groups.google.com&#x2F;forum&#x2F;#!msg&#x2F;uk.media&#x2F;KqhWP1rLF9U&#x2F;GK05lbwYuUcJ" rel="nofollow">https:&#x2F;&#x2F;groups.google.com&#x2F;forum&#x2F;#!msg&#x2F;uk.media&#x2F;KqhWP1rLF9U&#x2F;G...</a>