i.e. if you are using an adblocker, then the adblocker not only blocks ads but blocks the entire site.
If you're talking about giving legal power to websites' ToS to define what software may parse the data you download from their servers before/after rendering it to you, you're opening a gigantic can of worms, and I don't think most users would be particularly happy with that.
Seems reasonable to me that the adblocker should act responsibly and block entire sites where the TOS prohibits its use.
Not hard for sites to set something in robots.txt to say "no adblockers allowed"
This is not true in any country at the moment as far as I know. There's some initial stupidness in the US like https://www.washingtonpost.com/news/volokh-conspiracy/wp/201... , but in practice that's going to be disputed in courts many times before they agree on some final version.
Especially since there's a related recent ruling (can't find the article now) which basically said - if your ToS are too complex and people are unlikely to understand all the details, they're not bound by it.
If Facebook or any site wants to prevent people using ad blockers from viewing their content, that's their right. But an ad blocker that doesn't block all advertising, all the time, by default is just broken. Any exceptions should be explicitly made by the user, not the ad blocker or the site.
Second, exactly how would you force them? Do you really want a legal ban on the distribution of software that could permit the end user to violate a civil contract? That might fly in China and possibly the US, but probably not in the EU.
How do you force a program to do anything? Or how does facebook force you to use an approved adblocker?
An exercise: I say you can't use the internet with extensions I disapprove of. Do you comply?
popcorn time, napster.
Adblockers do not distribute copyrighted software. It's a different issue. While blocking ads could be challenged legally, it has not happened yet.
It seems likely to me that companies like Facebook will spend alot of money fighting adblockers. Not just in court but in Washington with lobbyists. The politicians know which side their bread is buttered on - laws will come into effect banning adblockers sooner or later.