Soccer fans planning to travel to the World Cup in Russia are being warned that if they take any electronic devices with them they're liable to be hacked.
Experts in the US and the UK are advising that any data held on a mobile phone, tablet or laptop - including personal data - could be accessed by state-sponsored actors.
"Corporate and government officials are most at risk, but don’t assume you’re too insignificant to be targeted," director of the U.S. National Counterintelligence and Security Center William Evanina tells Reuters.
"If you can do without the device, don’t take it. If you must take one, take a different device from your usual one and remove the battery when not in use."
Meanwhile, the UK's National Cyber Security Centre (NCSC) has been working with the England squad, adding an extra layer of security software to protect the team's devices. In the past, British sports stars including Sir Bradley Wiggins and Chris Froome have been targeted by hackers looking to steal their personal and medical data.
The team's also been told not to use internet banking while in Russia - or to do anything potentially embarrassing online.
Meanwhile, many Football Association staff have been told to leave their personal devices at home.
However, the NCSC agrees that fans are at risk too. They should consider taking a 'burner' or pay-as-you-go phone, it advises, and should make sure they have the ability to wipe the phone's data, should it be stolen or lost. And all devices should be password-protected, with two-step authentication enabled where possible.
According to security firm Kaspersky, fans should be particularly wary of using public wifi, with more than 20% of public wifi spots in 11 FIFA World Cup 2018 host cities found to be insecure.
"The lack of traffic encryption, coupled with large-scale events – like the FIFA World Cup - make wireless wifi networks a target for criminals who want easy access to user data," says senior security researcher Denis Legezo.
"Despite about two-thirds of all access points in FIFA World Cup host cities using encryption based on the most secure wifi Protected Access (WPA/WPA2) protocol family, even these access points can’t be considered secure if the password is visible to everyone."
Fans are being advised that if they really must take their devices with them, they should use a virtual private network - frowned upon, to say the least, by the Russian government, but unlikely to actually get them arrested.
