At last, the music industry admits what we've known for years: That filing music-swapping lawsuits against teenagers, little old ladies, and corpses is a fool's errand (not to mention an expensive headache for the defendants). But don't worry—the RIAA has something new up its sleeves.

The new strategy (as reported by the Wall Street Journal): If the music industry finds out that you're swapping music files online, it'll send an e-mail to your ISP (agreements have already hashed out agreements with "some" unnamed service providers, apparently), which will in turn forward the message to you—probably with a little "P.S." asking you to stop. [Update: CNET has a copy of the RIAA's form letter to ISPs.]

If you don't stop, well ... your service provider probably won't sue you, but it might slow down your broadband connection, or cut off your service altogether.

So, why has the RIAA changed the play? Well, maybe it's been looking at reports like this one from the NPD Group, which shows that U.S. CD sales continue to slide, while the number of tunes shared via P2P sites continues to increase, despite all the litigation.

And then there's the disastrous headlines, as the RIAA relentlessly tracked down and sued tens of thousands of alleged music pirates. Among them: Kids, octogenarians, and a few dead people.

Reaction to the news? Mixed. Engadget's headline reads (in part): "RIAA finds its soul," with the story noting that while the RIAA reserves the right to go after "heavy uploaders or repeat offenders ... it appears that single mothers are in the clear."

All Things Digital has a darker outlook, speculating that ISPs—which "care about the cost of moving lots of data around … [and] want to make money by selling, renting, or just offering up Hollywood's movies and TV shows to subscribers"—might be more than content to "cut off file-sharers … [or] simply [charge] heavy file-sharers a lot of money."

And here's another possibility, courtesy of yours truly: Say your ISP catches you sharing tunes via P2P. No problem—download away! But when you get your next cable bill, you'll find the itemized songs added to your monthly charge, kind of like an iTunes bill.

Call it the "if you can't beat 'em, join 'em" strategy.

P.S. Make no mistake—just because the RIAA has stopped filing new music-swapping lawsuits doesn't mean that it's dropped the existing ones, according to the Journal. Quite the contrary.

Related:
Music Industry to Abandon Mass Suits [Wall Street Journal]