As a casual browser I can only blame the site that &quot;served&quot; me, good and hard. I have no idea what network or subnetwork ultimately served the malware&#x2F;ad.<p>And since the visited site is the one that came into my &quot;home,&quot; it&#x27;s entirely appropriate to hold the site&#x27;s feet to the fire.<p>When a site becomes well known for holding itself responsible for what comes out of the site, and doing it effectively, I&#x27;ll whitelist them.