Not too long after Twitter bought its own live-video streaming company, it's cutting off the competition's access to its infrastructure. We're talking about the new, social-broadcast video darling Meerkat, of course. As Buzzfeed's sources tell it, the microblogging service began taking steps to break Meerkat's access to the Twitter social graph this evening, just as the former was gaining traction at tech's big coming out party, South by Southwest. A Twitter spokesperson confirmed that the video outfit'd been officially cut off, and said that the imposed limits are "consistent with our internal policy." That doesn't mean you can't log in to what amounts to a phone-based Ustream via your Twitter username, sync your follow list between the two or post tweets once you start streaming -- it just might be a bit janky for awhile.