The Russian sites have been tested in Russian courts and found to be legal. The question is it legal to buy it if you like outside Russia? It depends on who you talk to, about it. The RIAA has never gone after them because of this I suspect " This is because of the Berne convention as administered by the WIPO, and WTO requirements.
I quote “…any country that is a signatory of the convention is awarded the same rights in all other countries that are signatories to the Convention as they allow their own nationals, as well as any rights granted by the Convention” . The fairest seems to be emusic.com they appear to pay the artists , it is higher quality and much less. I would not mind paying more for music but 128k and poor quality at $1.06 USD a track is a lot.