App Tracking Transparency Policy
Apple's decision to change the privacy settings of iPhones is believed to have resulted in over £7 billion in lost revenue for social media companies.
The tech giant introduced its App Tracking Transparency policy in April.
The setting forces developers to ask for permission to monitor the behaviour of users.
Facebook, Twitter, YouTube and SnapChat say the changes affected the accuracy of ads, increasing the costs for clients.

Andy Burnham Sworn In As British Labour Leader
Phased Social Media Age Restriction Being Proposed By European Commission In September
US Launches Fresh Strikes On Iran
Pitbull Fans Set Bald Cap World Record In London
Ceasefire Under Threat As US Attack Iran Overnight
Nigel Farage To Resign As MP And Run In By-Election
MEPs Meeting This Morning To Discuss Ireland's EU Presidency
Member States Responsible For Suspending EU Trade Agreement With Israel - Von Der Leyen