If you ran down the stairs on Christmas morning, hoping to find an iPad or a puppy or a Lexus with a bow on it under the tree, then, apparently, you're doing it wrong because everyone else got assault rifles. A whole slew of people received AR-15s for Christmas ('tis the season) and were so excited that they just couldn't contain themselves—they HAD to let the world know about their new gifts by posting on Twitter and Instagram. In case you missed it, the AR-15 is the type of gun that Adam Lanza used during the Sandy Hook massacre earlier this month and by William Spengler when he ambushed firefighters in New York on Christmas Eve.