Skype, the voice/video/messaging service used by millions, has run into a little irony problem. The mobile application interface Fring announced on Monday that Skype "is refusing to allow fring to restore connectivity" to the service, and has been "forced to stop its 4 years of Skype interconnectivity following threat of legal action."

The news comes following Fring's recent rollout of its two-way video calling capability over WiFi and 3G.

Reproachful comments accompanied Fring's disclosure. "Needless to say, we are very disappointed that Skype, who once championed the cause of openness is now trying to muzzle competition, even at the expense of its own users," the company declared on its blog.

They are afraid

Fring offers mobile users software that aggregates a wide variety of instant messaging and conferencing apps, so that consumers don't have to manage Skype, Yahoo, Twitter, and the like on a separate basis. The dig at Skype refers to the fact that the company has famously called on the Federal Communications Commission to extend its Carterfone open device principle to wireless technology—requiring wireless carriers to offer access to any device or application that doesn't hurt the network, as landline common carriers must.

And, of course, there was that huge to-do about AT&T not allowing Skype to transmit across the iPhone's 3G network, which became quite a cause until AT&T reversed course.

So here's Skype, supposed avatar of openness, closing down access to Fring.

"They are afraid of open mobile communication," Fring's blog post intemperately added. "Cowards."

But is that really the case?

"I want to make one thing absolutely clear: this is untrue," pushed back Skype's Robert Miller several hours after the Fring broadside.

In breach

Fring was "using Skype software in a way it wasn't designed to be used," Miller insists. And that put Fring "in breach" of Skype's API Terms of Use and End User License Agreement. Among other offenses (to Skype), Fring just announced that it is "temporarily reducing support to third-party Skype" as a consequence of the huge boost in two-way video calling it is now handling.

"Fring's mis-use of our software was increasingly damaging our brand and reputation with our customers," Skype charges. The withdrawal of support was "damaging our brand and disappointing our customers, who have high expectations of the Skype experience."

There was is "no truth" to Fring's blocking claims. "Fring made the decision to remove Skype functionality on its own."

Hopefully this can be resolved without anyone else getting called a coward. We did wince a little at Skype's assertion that Fring has been using Skype "in a way it wasn't designed to be used." Two years ago Comcast deployed almost those same words in response to tests indicating that the ISP was blocking BitTorrent transmissions.

When BitTorrent is used "as designed to be used," Comcast's David Cohen insisted, it runs fine on the cable giant's network.

To be fair, Skype is talking about third-party access to its own software here. But remind us again who gets to decide how these apps should be used? Skype may well have a strong case. We'd like to see more details.