Twitter's biggest users are no strangers to hackers. Whether due to malicious email attachments or weak passwords, everyone from Lady Gaga to Barack Obama to Ellen DeGeneres has been a target.

Having your account hacked is invariably embarrassing, but the stakes are far higher when malicious messages are sent from a high-profile user like Justin Bieber, who has some 12+ million followers.

The worst hack on record was a Jan. 5, 2009 takeover of some 33 tweeters' accounts. In efforts to reduce the phenomenon, Twitter has banned more than 400 passwords deemed too "obvious."

Among Twitter's top 11 users, Taylor Swift and Shakira are the only two to never experience a hack.

This Vercode infographic explores some of the biggest hacks.

Infographic by Veracode Application Security