Katy Perry's Twitter was hacked on Monday (May 31).

The singer's account posted a series of messages on the social networking website, including "miss u baby" to reported rival Taylor Swift.

The hacker also used some racist and homophobic language and added: "#HackersGonnaHack".

The tweets were deleted with Perry instead taking to the platform to honour Memorial Day.

The singer is the most popular person on Twitter with around 89 million followers.

Justin Bieber is the second top user with over 82 million fans.

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