I think with automated reservation systems, there should be a sliding scale for cancellations.
1. Reservations cancelled at least 3 months out should not incur a fee or at most a minimal one for processing.
2. Reservations must be cancelled in full and then the account must wait 24-48 hours to re-reserve at the same campground during the original reservation period. So if you book August 1-15, you would have to cancel the entire reservation and wait 24-48 hours to reschedule for August 11-15.
The sliding scale for reservations less than 3 months out, could be something like:
First cancellation within a 12 month period incurs a 10 percent cancellation fee.
Second cancellation incurs a 50 percent cancellation fee.
Third cancellation incurs a 75 percent cancellation fee.
Fourth cancellation incurs a 100 percent cancellation fee and a 1-year ban from reserving again.
This could be established by campground ownership rather than individual campground. So making a season's worth of reservations at multiple state parks and cancelling four would ban you from reserving at all the state parks for the next 12 months. You could stay using FCFS sites, but wouldn't be able to make reservations.
And if the vehicle/RV license plate(s) were required at the time of reservation, it would help prevent folks from making multiple accounts. Having a camp host or ranger just verify the plates after arrival and create a flag on the account if different than listed could further deter cheaters.
1975 American Clipper RV with Dodge 360 (photo in profile)
1998 American Clipper Fold n Roll Folding Trailer
Both born in Morgan Hill, CA to Irv Perch (Daddy of the Aristocrat trailers)