There are a lot of barriers to me going 'dark'. I teach at a public university. A great deal of my electronic correspondence relates to my dealings with, and through, that institution. I have no meaningful control over how visible those are.
Worse still: Child Support Agency and Centrelink. Both expect regular updates - despite everything they need to know being already held by the ATO ...
Fundamentally, my issue across this whole problemspace is that more just makes it harder to focus. On anything.
I have been working on a doctorate examining the FUBAR that is 'balancing' privacy and security implications at the intersection of law, public policy, and technology for far too long now. This whole space is a mess of ideology and politically-motivated assumptions. MORE 'data' isn't going to help predict or protect anything or anyone; and it certainly makes litigation/prosecution more complex and tedious (notwithstanding the ridiculous Kafkaesque "anti-terrorism" legislation), supposing some intervention operation does snag a nefarious outlaw. [Similar laws have failed to quash the criminal activities of guys-on-bikes, and those guys are generally just after more cash moneys.]
I could try to go dark. I may even be successful. But I'm interlinked with so many other people, that my shadow alone is enough to figure out much of what I could be obscuring. [FWIW: I probably do keep some of my activities cloaked. But I wouldn't confirm or deny anything around that. Whether I do or don't do anything that is untoward ought to require more than the say-so of some keyword scanner.] Relying on some black-box to make decisions about people's lives is inhumane and dehumanising. [Avoids invoking Godwin's Law]
I am quite scrupulous about not hiding anything from the ATO. I like being able to choose what I eat, and when and where I lay myself down to sleep.