I've never had any problems with break in's in the park. Could be because my stuff is junk
. Just try to park in open easily seen areas.
The tailwater guys on the southeasternflyfishingforum.com sound like they have major problems. Apparently the local law has problems with whose juristiction is what and the offenders getting slaps on the hand. I hope this doesn't carry over more into the park than it has.
I try not to carry a lot of gear in a car parked at a trailhead. If I am camping, I keep my extra rods, etc. in my tent or camper. I make it a practice to open rod tubes, tackle bags, etc so someone looking in would see they are empty. Watch were you park.