????After six years of waiting, the day Michael Robertson always knew would arrive finally got around to arriving. On Tuesday Robertson, the former CEO of MP3.com and general digital music gadfly, read the news that Google (GOOG) was releasing a service that allowed people to upload their music to the cloud. A few weeks earlier, Amazon (AMZN) had released its own product, Cloud Drive, that let people listen to their music on whatever computer/phone/web-connected phonograph they wanted, even if the music wasn't actually stored on that device. After years of promises it seems the future, or at least the one that involves omnipresent music, has finally become the present.

????Except Robertson built that future five years ago. That's when he self-funded MP3Tunes.com, a site that does more or less exactly what Google and Amazon's cloud lockers do. And yet it's the big guys' debut that garners the attention. "It's always a bit frustrating because every time Microsoft (MSFT) scratches their nose, everbody writes about them. Every time Google changes their hair, everybody writes about them. Every time Amazon does something everybody writes about them," Robertson says.

????This is, of course, not a problem unique to MP3Tunes. Many startups' only vote of confidence comes when a bigger company copies its idea. But Robertson appears to have a strategy to not get swept under. He's going vigilante.

????It's not a new affect for Robertson. Fighting lawsuits from the music industry appears to be a hobby. Why else would he keep return to the same record record labels' litigation had already tainted it? In 1997, he founded MP3.com, and soon thereafter was in court, defending the site's habit of giving people the rights to a digital copy of a song if she could prove she bought the CD. (MP3.com settled with Universal Music Group for $54.3 million in 2000.) MP3Tunes has been no different. For the past few years he's been battling a lawsuit from EMI, which claims copyright infringement and requested access to the lockers of MP3Tunes users. A small court gave MP3Tunes a partial victory, but the case is ongoing.

????None of this has stopped him from moralizing MP3Tunes' cause. In fact, it's only encouraged it. According to Robertson, the struggle against the record labels is one of the defining business and legal battles of our time. About EMI's suit against MP3Tunes, Robertson reportedly said, "If we lose, the whole notion of online music storage goes away." All-or-nothing comments like those have made him the leader of a fledgling movement that now includes Google and Amazon, and likely Apple in the near future.

????But while Google is still trying to play relatively nice (even with statements like these from its director of content partnerships: "[But] a couple of major labels were less focused on innovation and more on demanding unreasonable and unsustainable business terms."), Robertson is not. Honed by years of lawsuits, he's fashioned himself into a crusader for the consumer, determined to overcome the music industry's reluctance. After Amazon and Google's cloud music services were released, he wrote posts on TechCrunch and Silicon Alley Insider (which, as tech status symbols go, are the diluted equivalent of a Fortune 500 CEO publishing an op-ed in the Wall Street Journal) about the hurdles for the industry. And in posts on his own blog, he makes his problem the world's problem. "If it's illegal for MP3tunes to store music files on its servers then it's illegal for Google to store music files in its servers too - even if they're email."

????All of this effort theoretically helps attract people to MP3Tunes' actual service, which is as advanced as it is maddening. You can listen to the music you upload from nearly any device, thanks to MP3Tunes' API. That's something that neither Google nor Amazon let you do. But actually getting that music up into MP3Tunes takes a ton of time. The few tracks I uploaded took a few minutes each. Robertson told me it was because I was using a cable broadband connection, which is notorious for slow upload speeds. The same issue will affect the established companies, as well. (The slow upload problem is so significant that MiMedia, another media storage service in the cloud, sends subscribers a hard drive that they can then load up with tunes and send back to the company to put onto the cloud.)

????That kind of hurdle is why MP3Tunes, despite six years on the market, still has fewer than 1 million users. And that's total users. Robertson wouldn't share how many are still active on a monthly basis. And it's why, even with the size of Amazon and Google's bully pulpits, cloud music may never quite takeoff for consumers, at least not while most Americans' broadband connections resemble a highway for downloading, but a country road for uploading. But now, people are paying attention. Google, with its huge fiber-optic capacity and high-speed pilot project in Kansas City, Kansas, is paying attention.

????If there's any benefit for Robertson in watching established tech companies following his years-old footsteps, it's exposure. "There is this benefit that once the big boys start getting into the business, then Fortune gives me a call," Robertson says. [Editor's Note: Fortune ran a profile of Robertson back in 2003.] It may have taken six years, but Robertson's company is finally back on the map. Assuming, of course, a judge's verdict doesn't sweep it right off.