The Black Keys have been a vocal opponent of Spotify before. Only this time they've called an important music/media tech guy and "assh*le." Oh gosh!

Black Keys drummer Patrick Carney clarified the band's stance to Grand Rapids, Mich. radio station WGRD this week, indicating that the streaming service's royalties scheme doesn't have enough of a payout for the band to make all releases available.

"The idea of a streaming service, like Netflix for music, I’m totally not against it. It’s just we won’t put all of our music on it until there are enough subscribers for it to make sense," he said. "Trust me, Dan and I like to make money. If it was fair to the artist we would be involved in it... I imagine if Spotify becomes something that people are willing to pay for, then I’m sure iTunes will just create their own service, and they’re actually fair to artists.”

To be clear, most Black Keys releases are on Spotify, just not 2011's "El Camino." Part of the basic math is that a band must pay an upfront cost to be on Spotify, of course, but then if a new or popular release is available on the service immediately, then streams could take away from a album or single sale. Users on Spotify can upgrade to paid subscriptions, of course, generating revenue for the service and for labels/publishers/rights holders. They make money on advertising to non-subscribers.

During the South By Southwest Music and Interactive Conference this month, Spotify part-owner and former Napster founder Sean Parker had a rosy outlook on Spotify's future in that regard. He surmised that Spotify could catch up to iTunes in terms of revenue in two years. (For giggles, Spotify would need $2.08 billion in revenue -- or 12.34 million U.S. subscribers -- in 2013 to make that work.) For the U.S., that's difficult to imagine, though it may work in other countries.

To Carney: no matter. That money benefits labels more than it does the individual artist, as Spotify releases that revenue to rights holders for them to dole out.

"[Parker's] an assh*le. That guy has $2 billion that he made from figuring out ways to steal royalties from artists, and that’s the bottom line," Carney said. "I honestly don’t want to see Sean Parker succeed in anything."

That's the past biting you in the butt. Not only was Napster hyper-controversial at the time it was launched, but in a legitimate business practice Parker could still be accused of improper payout. Led Zeppelin, Tom Waits, Pink Floyd, AC/DC, former Napster foes Metallica and others agree, which is why you won't find selct albums or entire catalogs on there.

The Black Keys -- among those names, anyway -- are still newer artists, and their audiences engage with music tech more often and in more ways than older listeners do, by and large. So using Spotify for younger bands and smaller bands still presents a quandary: you want to make your product as available as possible to as many people as possible, don't you?

But then there's some responsibility on the label to be fair with the royalties, and its not like the Black Keys' label Nonesuch are running a non-profit. Were the Black Keys their own exclusive rights holders, then this might have been a different conversation entirely. Just look where you sign the dotted line, kids.

And in case you're still wondering about another Black Keys beef -- with name-calling Nickelback and their fans -- Carney half-heartedly apologized. "I didn't mean to single them out. It just came out," Carney told MTV Canada. "There's much worse bands than Nickelback, maybe."