PR firm Webber Shandwick says that this is most likely because of the high profile casualties of Twitter, such as Rupert Murdoch’s tweets (‘scumbag celebrities’) or the former CEO of General Electrics, Jack Welch, who tweeted that Obama was fudging job numbers because he ‘couldn’t debate’. It’s also thought that CEOs do not like being limited to the 140 character rule and would rather a platform that allows them to express themselves in longhand.