Facebook has confirmed a TechCrunch report that it is developing a tool for advertisers to verify they have gained consent to use email addresses uploaded via Custom Audiences.

Facebook’s Custom Audiences make it possible for advertisers to target users on its platform by uploading lists of emails, phone numbers and other data and cross-referencing it against user profiles.

According to Facebook’s director of corporate communications, Elisabeth Diana, the coming certification — or permissions — tool will require an advertiser and the agencies or other entities that obtain data to confirm that the third-party data in a Custom Audience has been responsibly sourced.

Right now, users can see which advertiser lists they are included on by viewing the “With your contact info” tab in the “Advertisers you’ve interacted with” section of the Ad Preference settings page. This includes advertisers that are currently running campaigns with Custom Audience lists. Users can remove the advertiser from the “Advertisers you’ve interacted with” page.

The new tool is in development, and the process for how it will work is still being explored, but Diana says Facebook plans to launch it soon. Without any details around how it will work or what the process will be, the feature could be as simple as a checkbox for advertisers to confirm they have consent to use data, or it may be a more complex set of permissions.

Diana said the added protection is not being implemented in response to the coming General Data Protection Regulation GDPR in the EU or the scandal around Cambridge Analytica’s misuse of Facebook user data but is a continuation of Facebook’s efforts to protect users. She added that Facebook is looking at other ways to protect user information within Custom Audiences.

This latest announcement follows a number of recent updates to Facebook’s advertising platform since the Cambridge Analytica news broke. On March 23, Facebook removed audience reach estimates for Custom Audiences after a vulnerability was detected by outside researchers for a second time.

Last week, the company updated its privacy controls for users and ended its third-party “Partner Categories” program that allows advertisers to target ads based on purchasing behavior, demographics and other data sourced from data brokers such as Axciom and Epsilon.