Net neutrality has seen headier days, and to be honest, it never stood a chance in the wireless industry — but T-Mobile just drove the point home at its "Uncarrier 6.0" announcement in Seattle this evening.

With a new initiative it's calling Music Freedom, a handful of music services will be blessed by the carrier so that they don't hit subscribers monthly data allowances. (T-Mobile doesn't charge overage fees, but throttles data speeds once users reached prescribed limits.) The list of Music Freedom-compatible services currently includes Pandora, Rhapsody, iHeartRadio, iTunes Radio, Slacker, Spotify, Samsung's Milk, and the forthcoming streaming service from electronic music destination Beatport. It'll also be taking votes from customers through its website and on Twitter for other services to add to the list of exemptions.

Subscribers can vote on new data cap exemptions

It sounds wonderful — and right in line with the "uncarrier" image that firebrand CEO John Legere has worked so hard to cultivate — but it's a terribly slippery slope: T-Mobile has decided, arbitrarily, that some of the data traveling over its pipes should count against a cap, while other data should not. What's to stop it from using data cap exemptions as a punitive measure against content providers that aren't on good terms with T-Mobile (or its parent company Deutsche Telekom)?

The carrier, naturally, doesn't feel it's an issue. "Our position on net neutrality — our regulatory position is that we don't think this industry needs to be regulated with such a heavy hand," says T-Mobile's Andrew Sherrard, noting that it isn't charging music services for the privilege of being exempted from the caps. But that's not the issue: the issue is that there are any commercial exemptions at all. (It's worth noting that AT&T frequently agrees that a "light regulatory touch" is best.)

"Our regulatory position is that we don't think this industry needs to be regulated with such a heavy hand."

Of course, as the open internet goes, wireless networks have never been treated with the same regulatory scrutiny as their wireline equivalents: even when the FCC's now-endangered Open Internet Rules were spelled out in 2010, it was very careful to carve out broad exceptions for wireless. By the letter of the law, T-Mobile is most certainly doing nothing wrong here, but that doesn't mean it's not setting a dangerous precedent.

Other carriers are undoubtedly taking note. While T-Mobile isn't charging any content providers for the cap exemptions, AT&T is getting into that game with its Sponsored Data program. It's exactly what it sounds like: someone pays for you to get around your normal data usage. What are the odds you'd use Spotify if Google paid AT&T to exempt Play Music, for instance?

So while T-Mobile's move will be perceived as an altruistic and competitive one — "Music should have no limits," Legere says — it's important to look at this as a domino, a seemingly innocuous tile that's rocking back and forth. At the end of that long domino line lies a weird, broken, disjoint place that looks nothing like the internet we know today.