Who cares if you spy on Russia though? Maybe they're looking for spambot lairs.
The Russians sure do.
Russia, however, is not on the US friend list. In fact, I might be so bold as to say that, perhaps, spying on the world power most antagonistic to US interests is, well, justified? The US isn't exactly spying on an ally or something less-then-legitimate like that. I mean the Chinese are playing the spying game on the US, and they aren't even directly opposed; and France is famous for it's spying*, and they're friendly, so it isn't like spying between world powers is surprising, or even unorthodox historically. And it isn't like Russia doesn't spy on the US.
As for the Norway connection, I suspect the Russians operate assuming the US is spying on them somehow anyway, and are more likely to be actively hunting down US spies or stopping US methods; and that substantiated claims of spying on them damage their fragmented but necessary (for bilaterally dealing with issues) relationship. Norway would be unexpected, their spies and intentions unknown to the Russians, their proximity a boon, the damage from possible exposure not directed at the US. Clearly Norway signed off on it willingly, and the article helpfully notes that Norway is one the claimants to the Arctic resources, and Norway has reason to support the US over a closer, more aggressive claimant.
Has it been Snowden's work releasing this? Because I can only find one source saying so, and I prefer a, wider base of source first. In any situation, I think there are more important concerns then the fact that the US spies on Russia. I hear he is attempting to gain asylum in Brazil, where angry Brazilians want to hear him speak.
*So much so that they didn't join the Five Eye community specifically because they couldn't spy on those countries; the fact that their previous records of spying would be available also didn't help