Is it just me, or does that seem terribly scummy. I'm not sure I'd consider inserting additional ads to be an ethical problem, as long as it was clear which ad

Is it just me, or does that seem terribly scummy. I'm not sure I'd consider inserting additional ads to be an ethical problem, as long as it was clear which ads came from the browser plugin, and which ones came from the website. But IMHO replacing the website's ads is scummy.