Heres a copy of the logo I designed and had printed onto tshirts etc for the Mad Max 25th Charity Auction held in December 2004. This image is copyrighted and under no circumstances can it be used without permission. Hugh Keays-Byrne now holds all rights to this image as I gave him the exclusive rights after the event.
It is interesting to note that Johnny the Boy does not brandish this tattoo until AFTER he has killed The Goose. Since The Night Rider is referred to as "A cop killer" in the beginning and since all the main members are seen with the tattoo except Johnny who is "In training" until after he has killed, the symbol, that is in the shape of the Greek letter "F" (a small circle with a vertical line running through its middle) the tattoo is an indication that the members are "Killers". And since George Miller has been known to put in references to his Greek heritage throughout the Mad Max franchise (The writing under Roop's feet in the opening is written in Greek saying "Fuck Greece" and the name Pappagallo is given to the leader of the survivors in Mad Max 2 which is the Greek name of a talking parrot) It is likely that the "F" symbol given to a Toecutter member AFTER they have taken a "Bronze" life is that of the Greek word "φονιάς" (foniás) which means "Killer"
