Google yesterday sent a cease-and-desist letter to Microsoft, demanding that its rival remove the YouTube app built for the Windows Phone platform.
The letter cited violations of the YouTube and YouTube API terms of service, including preventing the display of advertisements -- the way YouTube reaps revenue -- allowing video downloads and playing videos that partners have blocked on certain mobile devices.
"We request that you immediately withdraw this application from the Windows Phone Store and disable existing downloads of the application by Wednesday, May 22, 2013," the letter read. "We were surprised and disappointed that Microsoft chose to launch an application that deliberately deprives content creators of their rightful earnings, especially given that Windows Phone 8 users already have access to a fully-functional YouTube application based upon industry-standard HTML5 through the Web browser."
Microsoft, which built the YouTube app for Windows Phone, launched it May 8. Although Microsoft's Windows Phone Store does not disclose the number of downloads for any app, the YouTube app has been reviewed by more than 9,000 users and as of Thursday, was the fifth-most-downloaded free app in its catalog.
The Verge first reported the Google letter Wednesday afternoon, with Wired following minutes later. Neither revealed how they obtained the document.
Microsoft issued a statement Wednesday after the Google demands became public.
"YouTube is consistently one of the top apps downloaded by smartphone users on all platforms, but Google has refused to work with us to develop an app on par with other platforms," Microsoft said via a spokeswoman. "Since we updated the YouTube app to ensure our mutual customers a similar YouTube experience, ratings and feedback have been overwhelmingly positive. We'd be more than happy to include advertising but need Google to provide us access to the necessary APIs."
Ezra Gottheil, analyst with Technology Business Research, saw no end to the tit-for-tat, back-and-forth between Google and Microsoft.
"They're both contending for the territory where, by all accounts, Android has largely won," said Gottheil of the smartphone market. "Microsoft is an aggressive and feisty company, [so] this will continue, whether it's done publicly, or a behind-the-scenes chess match."
Microsoft has been the aggressor most of the time, said Gottheil, who ticked off Redmond's "Scroggled" attack ad campaigns and its pursuit of patent licensing fees from smartphone makers who rely on Android to power their devices.
"Microsoft has expressed its antagonism for far larger, but this is the first time I know where Google is fighting back in a public way," said Gottheil in a Thursday interview.
Google's CEO Larry Page, speaking at his company's I/O developers conference yesterday, called out Microsoft for not reciprocating.
"Take something as simple as instant messaging," Page said. "We've kind of had an offer forever that we'll interoperate on instant messaging. Just this week, Microsoft took advantage of that by interoperating with us but not doing the reverse. That's sad."
He attacked what he called "people milking off one company for their own benefit" as he referred to Microsoft's integrating Google Chat into its Outlook.com email service last week, while at the same time blocking efforts by others to tie into Skype. "We certainly struggle with people like Microsoft," Page added.
Microsoft made hay off that remark in its statement yesterday. "In light of Larry Page's comments calling for more interoperability and less negativity, we look forward to solving this matter together for our mutual customers," Microsoft said.
Gottheil saw Microsoft's move as another poke at Google but declined to speculate whether it was a strategic move, and whether Google's response was likewise. "But I don't see this as a net loss to Google," Gottheil said of the Mountain View search giant's cease-and-desist.
In fact, the two companies rely on each other more than the public dust-ups indicate. "There's a lot of contested territory, but for Google to run their fundamental business model, they have to provide support for multiple platforms. So it's not a zero-sum game. Windows benefits from YouTube on it, and Google benefits from YouTube on Windows."
Google and Microsoft have squabbled over YouTube before. In March 2011, Brad Smith, Microsoft's general counsel, announced that Microsoft had filed a formal complaint with European antitrust regulators, and credited Google's blocking of YouTube metadata as the reason.
"Google has refused to allow Microsoft's new Windows Phones to access this YouTube metadata in the same way that Android phones and iPhones do," Smith contended. "As a result, Microsoft's YouTube 'app' on Windows Phones is basically just a browser displaying YouTube's mobile Web site, without the rich functionality offered on competing phones."
Microsoft's YouTube app remains available in the Windows Phone Store.
This article, Google issues YouTube ultimatum to Microsoft as Hatfield-McCoy feud heats up, was originally published at Computerworld.com.
Gregg Keizer covers Microsoft, security issues, Apple, Web browsers and general technology breaking news for Computerworld. Follow Gregg on Twitter at @gkeizer, on Google+ or subscribe to Gregg's RSS feed . His email address is email@example.com.