the real world is complex, so I expect each person to think about the ethics of their actions for themselves.
however, that being said, I personally would consider many forms of advertising ethically suspect today (without coming into the debate of what constitutes advertising).
So all I'm saying is, if a mugger comes at you with a knife, or there's a dark alley, or someone places a GPS tracker on your car without your consent, or someone bombarded you with messages about how you're not sexy enough or your kids are stupid and you're a bad parent if you don't buy X because they profile you, then you can (and probably should) break or take the muggers arm/gun/ķnife, light the dark alleyway, smash the GPS tracker or reprogram it out send it fake signals, block their messages/throw them in the bin/destroy them respectively.
You often hear messages about how people are obligated to watch/respect/load advertisements from advertisers, and this is just patently absurd, especially on the web and in public places.
I have no ethical problems myself with using ad blockers or technology to waste the resources of advertisers, trackers and telemarketers. at what point you take to the streets and start defacing billboards, covering signs, tearing propaganda down, disabling severs, breaking screens etc, I can't say without context, but I would say from my perspective civil and active disobedience certainly isn't inherently non-ethical. private property rights do not trump all other rights or civil responsibilities in a reasonable and ethical society.