Brands and individuals that are testing out Twitter’s new video toy, Vine, are learning the hard way that it doesn’t play well with Facebook.

Sure, there’s a big button to connect your Vine account with Facebook so you can finds friends and connect more easily on the new video platform … but it’s broken.

As AllThingsD reported Thursday, Facebook cut off Vine’s ability to tap into the Facebook friend graph. Try it, and you’ll get a message saying that “Vine is not authorized to make this Facebook request.”

Facebook didn’t completely kick Vine out; after a video is made, users can still share it on Facebook. So it’s a one-way relationship: Vine can contribute content to Facebook, but Vine can’t get friends/connections from Facebook. (You can’t help but wonder if Vine will respond by turning off that sharing option; we’ve reached out to Twitter to see if they want to comment on that, but no response as of yet.)

Update: Shortly after publishing, a Twitter spokesperson emailed with an answer to that question: “Nope – you will still be able to share on Facebook.”

A Facebook spokesperson declined to comment to Marketing Land on the decision to cut off Vine, but it’s obviously about competition and data protection. Facebook knows that its social graph is valuable, so why share it with a competitor like Twitter?

There’s some history here, too. Twitter did the exact same thing last summer when it cut Instagram’s access to find friends via Twitter. Then Instagram decided in December that it wouldn’t allow user photos to display correctly on Twitter.

It’s not just a Facebook-Twitter thing. Also yesterday, Facebook blocked Russian search engine Yandex from accessing Facebook content for its new social app, Wonder. And, as TechCrunch reported last week, Facebook also cut its “find friends” access from the voice messaging service, Voxer.

Clearly, Facebook has every right — as does Twitter and any other company — to use its APIs in whatever way it thinks is best for the bottom line. But it’s awfully ironic, especially in Facebook’s case, considering that CEO Mark Zuckerberg declared last year in his IPO letter that the company’s “social mission” is “to make the world more open and connected” — a boast he’s been making for several years.

Facebook’s definition of “open” appears to be similar to Google’s; i.e., we’ll be “open” when it’s convenient for us.

Related Topics: Channel: Video | Facebook | Facebook: Business Issues | Features & Analysis | Top News | Twitter: Vine

About The Author: Matt McGee is Editor-In-Chief of Marketing Land. His news career includes time spent in TV, radio, and print journalism. His web career continues to include a small number of SEO and social media consulting clients, as well as regular speaking engagements at marketing events around the US. He blogs at Small Business Search Marketing and can be found on Twitter at @MattMcGee and/or on Google Plus. You can read Matt's disclosures on his personal blog. See more articles by Matt McGee

Connect with the author via: Email | Twitter | Google+ | LinkedIn