We stayed last Sunday in Upper Pines. When we came back to our site after rafting the Merced, a ranger was talking to our neighbors. Then, he came to our site and said (paraphrased) "I'm not here to kick you out or fine you, but I want you to know that you obtained your site illegally." I was floored, to be honest, because I had gotten the site on recreation.gov
At first, he said to me, well, this site was reserved by someone with a (Chinese name ending in Chan) and he wanted to know what website I obtained the site from. I told him that, no, that wasn't correct, but he wasn't convinced. I don't know if he thought we felt threatened and were lying, or what, not sure, but it took me producing my email printout of the confirmation to convince him that we had, indeed, gotten the site by legitimate means.
He had our site listed on his paperwork, but it was hand written and he said he had written down the site numbers at 4 am and was tired and must have transposed a number. I mentioned to him that I was aware of the scalping problem and he asked me to tell him everything I knew. Frankly, I know very little, I mentioned this site and that the ads are posted for us to flag, that was about all I could say.
When he left, my neighbors came over to talk. Turns out they paid 100 bucks a night to the scalper for their site. I was shocked to say the least. But he really didn't seem too concerned, stating that it costs more to stay in Oakhurst and drive in every day, which they had done on their last trip.