I used to work for the Forest Service patrolling these "ninja sites" as you call them.

We called them dispersed sites, as in not consolidated into a single area. They are

perfectly legal to use, and will likely still be legal way into the future, but you're right

Keith - we need to keep these places clean. I can't tell you how many people would

tell me (lie to my face) that they would clean up their site when they left and then leave

ALL of their trash, refuse, etc, behind. I even gave these people a large garbage bag to

put all their trash in! If I was lucky they would use the bag so that at least all I had to

pick up was the bag, but usually I had to clean up dispersed garbage in the dispersed

site (see the picture of my engine with a day's haul of garbage here:
http://www.flickr.com/photos/25976111@N02/2511550297/ )

On the other hand, however, there were people who cleaned up the garbage left by
others in the sites they were staying in. I once came across a retired couple who
had cleaned up the worst site on the forest, filling the entire bed of their pickup truck.
We sent them an official certificate of appreciation for their effort. I also had a group
of young adults (18-20) ask me for extra garbage bags so they could clean up more
trash - and they did this before they knew I was handing them out! These people
helped me maintain my faith in humanity, and kept me from automatically assuming
that everyone in the forest was an a**hole out to ruin everything that I liked about the
area.

Peter