First, if you want to get right down to it, here are the codes you type into Facebook chat to get various faces:
Huzzah! We are truly living in an age of wonder!
Second, why does this work?
There are various ways to bring Facebook content into chats. For example, you use Facebook Pages like a little TC by typing [[techcrunch]]. The numbers above are actually the IDs for pages that someone, for some terrible reason, made featuring all of those rage faces (https://www.facebook.com/pages/Poker-Face/129627277060203, for example). There are more to be found here thanks to Reddit so I’ll leave further discovery as an exercise for the reader.
All I can say is I’m glad there’s an Internet because the long minutes between sips of whiskey on Christmas Eve, spent staring malevolently at the fire, fingering my ratty smoking jacket, drawing from an unlit cheroot that had gone out hours before, and plotting the destruction of my many enemies would be a lot darker without the MeGusta face keeping me going. Happy holidays!