I wanted to mention that I use Freecycle a ton (both giving and receiving) and I do not mind if my stuff is picked up by resellers. It extends the life of the item as far as I am concerned, and that is my goal in Freecycling. If it keeps it out of the landfill, so much the better.
I don't mind resellers who buy from charities, either. Frankly, I'd rather people buy up clothes and resell them here, because that provides cash to the charities and in the case of the larger ones (Goodwill, Salvation Army, some of the church ones) it gives them less clothes to ship off to Africa and consequently depress the local textile market. Here
is more on that practice.
I think this practice is very ethically questionable. I haven't given anything to Salvation Army for years because I disagree with their policy on gays, but after I learned about the shipping to Africa, I stopped with Goodwill as well. All my used clothes go to our local women and children's shelter at this point, and I search out specialty charities for anything else. I like giving to people who will use the item directly, so as to better avoid sketchy practices like the African clothing bales.
I don't resell myself but definitely have no problem with it.