Ginni the stock spy!
"Buffett said IBM CEO Ginni Rometty "was out some weeks ago” to talk with Buffett about the matter after learning of his share sale through a private “stock watch” firm that Buffett seemed intrigued was able to spy on his selling pattern."
http://www.barrons.com/articles/ibm-will-the-stock-lose-its-buffett-premium-1493996486