It means/implies under the cover of darkness, or within a "black" box - un-seeable...A market place for anything illegal. Going full on, we could remove the wo

It means/implies under the cover of darkness, or within a "black" box - un-seeable...A market place for anything illegal. Going full on, we could remove the word "black" from our vocabulary. So hex #000000 would now be "abuefho" (some random made-up word) until people conscript that for their own designs and use it pejoratively: "you 'abuefho' jerk!"... and then round and round we go...