Facebook appointed three top executives to start a new internal blockchain team. David Marcus, former CEO of PayPal and current head of Facebook Messenger, will lead the group, joined by Instagram executives James Everingham and Kevin Will. The department shakeup acknowledges that blockchain technology could have a real purpose at large companies. The announcement also highlights blockchain as a potential threat to Facebook, such as blockchain messaging service Telegram and Jason Calacanis’ Open Book Challenge providing funding for building a Facebook replacement.