Facebook has once again introduced a new policy for self-regulation. Mark Zuckerberg’s omnipresent social network announced Wednesday that businesses that advertise to specific users need to specify where they got that user’s information and how they were targeted.

The new policy effects Custom Audiences, a tool that businesses advertising on Facebook use to upload lists of customers with contact information. If a company has access to a user’s phone number or email address because they did business with that person in the past, their ads will be surfaced to that user later on through Custom Audiences, for example.

After July 2, advertisers will be required to say exactly where they got a user’s personal information so they could be targeted by their ads, according to a Facebook blog post. Users can click on a “Why am I seeing this?” button on ads to see how they were targeted once this policy goes into effect.

Facebook will require some advertisers to disclose where they got customer information. An Indian man looks at the Facebook app on his smartphone in Amritsar on March 22, 2018. Narinder Nanu/AFP/Getty Images

As part of this change, advertisers will also be periodically reminded that they need consent to target people through contact info in this way.

TechCrunch had reported that Facebook in March was considering making this change. At the time, Facebook was in the midst of the Cambridge Analytica data scandal. There have since been concerns over how Facebook user data is disseminated to third parties, as relationships with election consulting firms, hardware manufacturers or advertisers have eroded some public trust in the company.

In its report Wednesday, TechCrunch pointed out that this change only works if advertisers are completely honest about where they got customer information. It might absolve Facebook itself of responsibility in the event of another data scandal stemming from Custom Audiences, but how much it actually stops companies from misbehaving remains to be seen.

This is the second customer-focused advertising policy Facebook announced this week. On Tuesday, Facebook revealed it would give users a way to report advertisers that sell misleading or faulty products on a regular basis. Enough negative feedback will result in lessened advertising for that company and potentially a complete ban.