Well, I would think it's pretty safe to say that none of the trades that occur are sanctioned by Lightfoot and he doesn't get any royalties from them.
The reason you all have had good trading experiences in the past is because the "regulars" here are good honest folks not looking to rip off Lightfoot or each other. They just want to see, hear and share as much of him as possible. These "regulars" would fight to be first in line should the same material ever become available commercially. However, the powers that be in the Lightfoot camp have already proven that they don't interpret it like that and have made thinly veiled threats of legal action (this came about in the News Group for those not familiar with my reference). This is why I always suggest that trades be done privately and not in the public forum.
That said, I think a good rule of thumb is when an individual only posts once and it is to peddle a trade and never joins in any of the other threads, he or she is probably not here for the communal joy of Lightfoot. No doubt, they are out to scam any who respond and should probably be avoided no matter how enticing their product sounds. But hey, maybe I'm just too cynical and untrusting