Privacy International (PI) has today urged England Manager Gareth Southgate to bolster his defence ahead of the World Cup in Russia, which kicks off next Thursday. PI sent Southgate an anti-surveillance 'Faraday cage' phone pouch and a briefing on his vulnerability to potential spying by rival football managers and foreign governments intent on giving their team a competitive advantage. If rival governments routinely hack and intercept each other's communications, what's stopping rival teams'…