They are not storing cookies but simply relying on if an ad blocker blocks ads.js or not:<p><a href="https:&#x2F;&#x2F;www.adblockanalytics.com&#x2F;ads.js" rel="nofollow">https:&#x2F;&#x2F;www.adblockanalytics.com&#x2F;ads.js</a>:<p>var d = document.createElement(&quot;div&quot;);
d.id=&#x27;abaA&#x27;;
d.style.display=&#x27;none&#x27;;
document.body.appendChild(d);<p>var abaA;
if(!document.getElementById(&#x27;abaA&#x27;)) {
	abaA = &#x27;N&#x27;;
} else {
	abaA = &#x27;Y&#x27;;
}<p><a href="https:&#x2F;&#x2F;www.adblockanalytics.com&#x2F;analyze.js" rel="nofollow">https:&#x2F;&#x2F;www.adblockanalytics.com&#x2F;analyze.js</a>:<p>var r = new XMLHttpRequest();
r.open(&quot;POST&quot;,&quot;<a href="https:&#x2F;&#x2F;www.adblockanalytics.com&#x2F;analyze&#x2F;&quot;);" rel="nofollow">https:&#x2F;&#x2F;www.adblockanalytics.com&#x2F;analyze&#x2F;&quot;);</a>
r.setRequestHeader(&quot;Content-type&quot;,&quot;application&#x2F;x-www-form-urlencoded&quot;);
r.send(&quot;abaI=&quot;+abaI+&quot;&amp;abaA=&quot;+abaA+&quot;&amp;abaSw=&quot;+screen.width+&quot;&amp;abaSh=&quot;+screen.height+&quot;&amp;abaBw=&quot;+window.innerWidth+&quot;&amp;abaBh=&quot;+window.innerHeight);<p>Don&#x27;t see any reason why an ad blocker would block them.