Handle errors resulting from paid allow-listing?

[dmarti]

In cases where

• the script is detecting ad blockers based only on an HTML element
• the user is running one of the "Acceptable Ads" ad blockers with paid allow-listing
• the site on which the script runs is not on the "Acceptable Ads" list

the user will be falsely marked as protected. See How to Debug Your Content Blocker for Privacy Protection from the Electronic Frontier Foundation

One approach is to check some resource loaded from a third-party domain, as the "Cover your Tracks" tool does with the eviltracker.net domain. See EFForg/cover-your-tracks: Is your browser safe against tracking?

A side effect of testing using a third party is that if the third party domain is on the widely used blocklists, then users protected with a DNS-based tool or Privacy Badger will receive a correct result (#16 #20)