I agree. While it is a great idea i think it is in the wrong spot. I think that sign should be at the corner below the spierbait stairs towards the lookout. not at the start of that fork of spiderbait. We often use that trail in the targa xc race.
At the moment you have a sign with a blue arrow on spiderbait pointing straight at another sign saying unauthorized trails beyond this point. It could definitely confuse someone.
Its all good for those of us that know the trails. But it might stop others from going down a blue trail that they would otherwise be perfectly ok on.