Better yet - number the WAG bags and mark down the numbers handed out (or have a barcode and scan them) on their permit.
Then the recovered WAG bags (at the end of the high season) could be traced back to a permit where they already have all the information on the person. Fines could be issued for those that leave them on the mountain. This could all be automated fairly easily and would not require much extra work beyond what is done now.
I'm sure word would spread very quickly once fines started being issued, and people would think twice before ditching their bag on the trail.
