Now Twitter was created in 2006. And Justin Bieber was born in 1994!
I present this as 100% proof of Time Travel.
Whoever the owner of Bieberlicious51 is, they time travelled back to 1992, they then found the creator of Twitter a certain Jack Dorsey. Bieberlicious51 then told Dorsey about Twitter. Dorsey then created an alpha version of Twitter which Bieberlicious51 made the first post on. Of course to stop a paradox, Dorsey would then wait 14 years before launching Twitter officially!