Yes. It's legally the same as counterfeiting only a little bit.
Some people do it out of kindness, not knowing it's just as illegal. But most know that they'll get more money if they hold something back- and that's where it becomes a sale.
A moral problem comes in because even the kind people hold back their best sets for "donations", and this harms the community. Not to mention, people are supposed to be donating out of appreciation for what they've already been given (the free sets), not what they might get.
"Only one or two donation packs" has a tendency to bloom over time, because sites want to keep people donating. And it fosters the idea that paying for files is acceptable and normal.
very interesting explaination. makes sense. shall we continue to plunder and pilige that which should be free??