"Unknown" means all of the generations addresses that could not be identified. It is not just one entity but all entities that could not be identified such as all solo miners, for one example.
Or all the manufacturers who take preorders and now running those machines while promising you delivery in June when the difficulty is nice and high and those asics are obsolete, so you can preorder their next batches/versions again.
I don't get the argument. Why would their pool be classified as "unknown" ? Also not all companies stealth mine. At least KNC doesn't
. Because they aren't using a pool in most cases. Then again the 'Unknown' number is also wrong, since it's using the blockchain.info 'Unknown', which is NOT unknown (at least the majority of it).
