Pace - What part illegal are you finding it difficult to comprehend? I'm sure the Nigerian in the Nissan is quite a reasonable driver, and his car in good servicable order, but if he is touting for business, it's illegal.
If caught someone doing illegal charters, I would punch the pilot, then call the Police, then call the CAA.
IT'S ILLEGAL 
and takes food off the table of those who work to the rules.
Not sure what pilots you are referring to? are you talking about unqualified pilots such as a PPL flying elegal air taxi work or an ATP type rated who happens to have chosen the corporate route rather than the AOC route?
All of the ones that partake in dodgy charters. Please don't insult my intelligence by trying to disguise illegal charters with legal corporate operations. I know the difference, so do you, and so do the idiots who claim not to know who partake in illegal charters. Ignorance is not acceptable in the aviation industry. If the CAA fined these morons £30k instead of £1'500 then it would help to deter them. there is simply no excuse for it.
FYI - I do name and shame, and have contacted a number of these "operators" sans AOC to let them know that I, and many others know what they are doing. Shame the CAA don't do it.
Perhaps I have spoken to you pace? - sounds like I either have, or will. Thou protesteth too much not be on the dodgy list me thinks.