Link to full article DMCA refers to the Digital Millennium Copyright Act, a controversial 1998 law that generally makes it illegal to circumvent technological protection measures that control access to copyrighted works. The law says circumvent means "to descramble a scrambled work, to decrypt an encrypted work, or otherwise to avoid, bypass, remove, deactivate or impair a technological measure, without the authority of the copyright owner."
MRT, based in Santa Cruz, Calif., argues that its X1 SeCure Recording Control technology has been "proven effective" as such a protective measure by plugging the "digital hole" that allows even copy-protected music streams, when played back, to be captured and potentially copied. The company says that because the companies are avoiding use of its purportedly effective product, they are violating the DMCA.
Creative legal argument but I don't see how it can win if taken to court. The law
does not require you to use "technological protection measures" as a copyright holder it forbids breaking them if you
chose to use them. So long as the media players do not break copy protection they are fully legal.