The safe/private thing to do is not visit any website at all. Ads don't have special access to your computer that a normal website does not. By visiting a new website, ads are by far the least of your worries.

Being online at all exposes you to risk and creates a footprint of your existence. Much like moving around in public does. And just as in moving around in public, the safest and most private thing to do is to not be in public at all.

You're ignoring opportunity costs, even in your meatworld analogy. There's real dangers to staying at home all the time, from social isolation to diseases of inactivity. Similarly, without using the web and visiting new sites, you're missing out on a lot of opportunity to communicate, learn, and yes, buy things. It may well be a lot less safe to avoid those things in the longer term.

Personally I block ads because I value my attention higher than advertisers value it. There is always an adversarial function built into ads; the advertising wants your attention, if nothing else, while I am interested in maintaining my focus. For similar reasons, I disable auto-suggest in Google search, animated gifs in the browser, and I use flashblock in all browsers that support it.

Anything continuously animated on the page whatsoever - no matter whether it's an ad, a subscription div popup, a "read next article" popup link, or a sharing toolbar - I block them all with element hiding helpers.

Because the greatest risk to me in browsing a random site is getting distracted and sucked down some rabbit hole. I use all the tools at my disposal to eliminate visual distraction.

You're right, there's risk in any action. The solution is to accept the risk, not to harm others while trying to protect yourself.

By blocking adverts, you're harming the people who make the things you like, in direct proportion to how much you like their content. The more you visit their site, the more load you make them pay for without giving anything in return.

If you're okay with harming others to keep yourself safe, and harming your ability to consume additional content from the people you want to consume content from, then fine. Continue to block ads. But know you're part of the problem, and are being selfish.

Ads don't have special access but because of their deployment across many different sites they get to track a much broader amount of your web activity than any individual site which in turn makes them a bigger privacy threat.

I don't block ads but I do use NoScript which means I rarely see them. It is increasingly common for pages to load scripts from dozens of different providers and those sites I generally turn away from.

Privacy threat? Because they want to serve you content you actually like? No, I don't think you know what a privacy threat actually is, then.

If you want to hobble around the web like it's 1995, that's your business. If you want access to content that's paid for by adverts, however, you need to be counted. That's the only way that content will be produced at all. You're not only harming the content producer, you're also harming yourself by lowering the number of interesting things in this world.