Apple is returning fire at Facebook as a public feud between the tech giants over customer privacy continues to escalate.
The social media company has been buying full-page advertisements this week in newspapers like the New York Times and Washington Post to attack Apple over the company's recent updates.
The changes mean companies using Apple products like iPhones to track their user's every move must inform the user of the tracking - and allow them to opt out if they wish.
Facebook argues this "will change the internet as we know it for the worse", forcing websites and blogs to start charging subscription fees or adding in-app purchases due to a loss in revenue resulting from a lack of personalised ads.
But Apple insists it's the right thing to do and notes it is applying the rules to itself, as well as any other company that produces apps.
"We believe that this is a simple matter of standing up for our users," Apple said in a statement.
"Users should know when their data is being collected and shared across other apps and websites - and they should have the choice to allow that or not.
"App Tracking Transparency in iOS 14 does not require Facebook to change its approach to tracking users and creating targeted advertising, it simply requires they give users a choice."
In its campaign attacking Apple's updates, Facebook says it is "speaking up for small businesses".
"Forty-four percent of small to medium businesses started or increased their usage of personalised ads on social media during the pandemic, according to a new Deloitte study," a Facebook ad reads.
"Without personalised ads, Facebook data shows that the average small business advertiser stands to see a cut of over 60 percent in their sales for every dollar they spend."
Apple began rolling out app privacy labels this week after announcing them in June, but has delayed full implementation until early 2021 to give developers more time to make changes to their apps.