This is definitely a concern. We've pretty much always been green, but it's hard to police after you leave, and usually we're gone before Temple Burn. (One year two of our camp mates stayed for Temple Burn and they ended up having to pack out two extra bikes that got dumped, in addition to having to deal with multiple people trying to camp in our empty spot. Maybe those people would've been fine, but given that they didn't understand the open camping situation, I'm unsure they understood LNT either.)