Yesterday, Vice President Joe Biden issued an embargo for his on-the-record press call, asking that reporters do not publish anything about the call until it's over. This includes Twitter, forcing journalists to wait to post live updates on the social stream. The reason? Journalists got to ask questions at the end of Biden's remarks, giving him the chance to clarify any questions before it's in print.
An email from the White House deputy press secretary Josh Earnest reads: