(YouTube, Getty Images)

It's a common known fact that teenage girls will scream for almost anything, especially if they are eagerly waiting for a glimpse of their favourite pop star Justin Bieber.

Another teenage boy, also staying at Justin's Melbourne hotel, decided to have some fun and film himself waving at the Bieliebers approximately 20 stories below.  At such heights it was easy for this look-alike to fool fans who were quick to scream. 

The real Justin was also having some fun playing pranks on this 25million fans via Twitter, Tweeting things like 'I'm going skinnydipping in Melbourne come find me!' and ''Do do do do do do do do do do' Those are the most meaningful lyrics on my album %u202A#catchingfeelings'. Many fans assumed his account must have been hacked.

What do you think of all the weekend pranks? Funny or cruel?