Honest, Mr. Ranger, a chipmunk ate my permit.
True story. I left my permit in an outside pocket of my backpack overnight, and I woke up to find that a local rodent had feathered its nest (or papered its walls) with my permit. The good news is that our wilderness ranger had met me the evening before, so we were all set.
But that's not true of all hikers. As I was hiking out, I met a hiker who had spent the night at Smith Lake. He noted that our same wilderness ranger had visited that lake as well, and instructed him to move his campsite farther from the water, But that wasn't the real story.
Because he'd also found a group that was hiking without a permit. The group apologized, and offered to pay the resulting fine to make it all better. (BTW--that's not the way it works. The permits are issued on an allocation basis, and there is usually no more room for extra people in the area---particularly true of Smith Lake, which has very few campsites.
Meanwhile, our ranger asked about a bear canister, They didn't have one of those either. The fine for that can be up to $5000.
The group decided to hike back out and head for home. And hopefully not only learned their lesson, but might very well share it with their friends. Or even better, post the story online!