Justin Bieber made his first tweet at 8:27 pm, promoting his single “One Time.”
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Psy's 'Gangnam Style' music video became the most viewed video on YouTube, passing 800 million views.
Chris Messina Tweeted #barcamp, which became the first use of a hashtag on Twitter.
The hashtag #5secondsofsummer trended worldwide for the first time on Twitter.
Elon Musk bought a 9.2% stake in Twitter, amounting to $2.9 billion.
Justin Bieber posted on Instagram that he has Lyme disease, a bacterial illness spread by ticks.
