Osama bin Laden’s death first leaked on Twitter. Chief of staff for former Defense Secretary Donald Rumsfeld tweeted, “So I’m told by a reputable person they have killed Osama bin Laden. Hot damn.” 2. When a cobra escaped from New York City’s Bronx Zoo in March, it soon showed up on Twitter @BronxZoosCobra, boasting about its adventures in the city. 3. From goal posts to gargoyles, people all over the world shared photos of themselves “planking” face-down on an innumerable amount of services, via Facebook and Twitter. 4. The moment Steve Jobs’ death was announced in October, social networks exploded with condolences, tributes and impromptu memorials for Apple’s founder and CEO. 5. Friday soon received an anthem of its own with the popularity of Rebecca Black’s video “Friday” that was uploaded to YouTube. The video received more than 167 million views.

Have one we missed? Let us know here!