P: https://forums.lanik.us/viewtopic.php?f=64&t=40299

easylist/easylist_whitelist.txt

@@ -812,6 +812,7 @@
 @@||f-cdn.com/build/js/ads/main.js?$domain=freelancer.com
 @@||facdn.net/art/$image,domain=furaffinity.net
 @@||facebook.com/ads/ajax/ads_stats_dialog/$~third-party,xmlhttprequest
+@@||facebook.com/ads/api/preview_iframe.php$subdocument,~third-party
 @@||facebook.com/ads/profile/advertisers/$~third-party,xmlhttprequest
 @@||facebook.com/ads/profile/interests/$~third-party,xmlhttprequest
 @@||facebook.com/ajax/feed/filter_action/dialog_direct_action_ads?$xmlhttprequest,domain=facebook.com