I have no ethical problem with ad-blocking
Our security subscription allows us to ad-block at our corporate firewall. I just had to enable the category "Advertisements".
It's funny, we have had a content filter available on our firewall for years, but never enabled it. Management has always been fairly liberal with filtering/tracking here at the company. They have always had the opinion that if they thought they had to nanny employees that much, they shouldn't be working here. In fact, they did terminate an employee a while back for abusing (and I mean really abusing) Farcebook.
It was finally the annoying ads that made us enable the content filter. So far, the only content we block is ads! It took a while for me to get the okay. There were some discussion about the ethics of ad-blocking, since we are a business that needs advertising. But, the recent stories of malware spreading via the ad networks finally sold it. It's the lack of policing their content that led to the blocking of ads at our company.
Everyone that works here is finally seeing how the web really should be!! People are coming to me to see how to get an ad blocker for their home PC.