"Dear FC Barcelona management, Don't let the Qatari money funds you, it's full of blood and kill," the hackers tweeted to FC Barcelona's 1.1 million Twitter followers.
Later, they added cheekily, "Special Hi to @ReadMadrid!"
Less than 20 minutes later, the football club regained control of the account and tweeted, "This Twitter account has been used fraudulently. The improper tweets have been removed. We apologise for any inconvenience."
"There seems little doubt to me that FC Barcelona could have avoided this hack if they had followed best practices -- which would have included training staff to never re-use passwords and to be suspicious of unsolicited emails, checked that they were only entering their passwords on legitimate websites, and -- crucially -- enabled two factor authentication on their account," Cluley noted.
Photo courtesy of Shutterstock.