Facebook's virtual assistant M is back -- and ready to underwhelm

Facebook's (FB, Tech30) first stab at an automated assistant, M could hold a coherent conversation, understand instructions and do your bidding. The early beta service, available to a handful of testers using Messenger, was powered by AI technology with a lot of help from invisible humans. On Thursday, almost two years after announcing the experimental feature, Facebook released a version of M to the general public. This M is not like the old M. Prepare to be underwhelmed. Instead of a full-featured assistant, new M eavesdrops on your regular Messenger conversations and then pops in "suggestions."