From the outside, Facebook and Twitter look like frenemies. Their now universal symbols sit side-by-side almost everywhere on the Internet, and they’ve made it fairly easy to crosspost from one platform to the other. But make no mistake, these two companies are bitterest foes, with each making cautious jabs into each other’s territories. There’s nothing either Facebook or Twitter would like more than to send the other packing, and Facebook’s working on a major blow right now: hashtags. They’ve been Twitter’s for a long time, and they’ve been one of Twitter’s most iconic symbols. But sources say Facebook is looking to bring them over (even if users have already been employing them for no apparent reason). #GameOn …