American pop singer Ariana Grande joined YouTube at 13 years old.
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A shooting took place at YouTube's headquarters in San Bruno, California.
Psy's music video for 'Gangnam Style' surpassed one billion views on YouTube, becoming the first video to do so in the website's history.
5 Seconds of Summer member Luke Hemmings posted his first YouTube video.
The 7-year old Ryan of 'Ryan Toysreview' was announced as the year's highest-paid YouTube star earning $22 million.
YouTube Live had the largest viewed broadcast ever, with guest artists performing from San Francisco and Tokyo.