I think that the quote works for Internet advertising because the similarity is that the bus company or building owner, like a web site owner, chooses to take money from advertising companies because they offer the best return vs effort return. For their money the ad companies try to jam their message into your brain.

The website as it displays on your computer using your computer memory and screen and CPU is your space, not the website's. So what Banksy says is even more true.

To use your analogy, your computer is your planet. If websites don't like that their ads can't get past your customs officers, that's their problem.

But I'm voluntarily visiting the place! Of course I'm using my resources doing that.

What's next: let the cooking magazine pay your electricity bill, because you decided to try out their recipe? Let the cinema pay for your glasses?

If your memory, screen or CPU is precious, don't visit that site. You know the deal and you have a free will. Use it.

And the site is voluntarily serving you their content.

Your cooking magazine argument is specious: you're not requesting the website pay your bills. The analog would be a magazine which assaults you with inserts, pop-ups, fragrance scents, a 90:10 advertising-to-copy ratio (and most of the copy is product placements), and charges you $10+ for the privilege.

Oh yeah: that's what they do. Which is why I don't buy magazines (with very rare exceptions).

>But I'm voluntarily visiting the place! Of course I'm using my resources doing that.

You could say this about the in person advertising that Banksy describes too.