There is a moral issue, you're right. Blocking ads is clearly morally permissible. Blocking ads is equivalent to not locking at billboards and skipping ad pages in a magazine (or tearing the pages out). There is no moral issue with any of that. You've bought a PC, you run whatever software you like on it. You have a right to chose how your machine displays content you download from the net. In turn, the maker of a web page can chose to offer whatever they want. If they need more money, then they can transmit the content only if you pay. That's perfectly feasible and reasonable. What they cannot and should be able to decide is how your machine displays their content and what kind of other software you use on your machine.
I believe that - if at all - only tightly controlled government authorities should be allowed to force display messages on end user machines, and if so, only in severe emergencies and for the protection of civilian lives.
People in this debate sometimes argue based on costs and money lost from ad revenue. These are business discussions that have no place in the moral evaluation at all. Not every business model works. So what, find another business model, is the answer.
Blocking ads is not morally permissible. Charging ads by the display is.
Any ad should charge the user by ad displayed or attempted to display, not by click or any other way. Just as TV advertisement. If the user goes to make a sandwich, skip it or remove the sound the ad should still be charged to owner of the ad.
Do you have any arguments for this opinion or is it an expression of a personal moral sentiment?
My argument why ad blocking is morally permissible is that it's a matter of the end users personal freedom if and how they display content from remote servers. They should be allowed to use a hex editor, plaintext, braille, TTS, a browser with or without ad ons, etc., and must be allowed to modify the content for their display purposes as they wish as long as they don't redistribute it. That's even a central idea of the HTML specification. There are also plenty of analogies to similar freedoms, for example if I buy a magazine (or get it for free) I can tear out ad pages and use them to fire my stove.
Redistribution is another matter and concerns copyright, but I just can't see any reason why the maker of a web page ought to have a right (or even feel entitled) to control my machine and how the data they voluntarily send to my machine is displayed on it. It's not as if anyone forces them to send the data in the first place.
I believe that - if at all - only tightly controlled government authorities should be allowed to force display messages on end user machines, and if so, only in severe emergencies and for the protection of civilian lives.
People in this debate sometimes argue based on costs and money lost from ad revenue. These are business discussions that have no place in the moral evaluation at all. Not every business model works. So what, find another business model, is the answer.