The "high taxation is not slavery, because you voted" argument lost all merit once net recipients of the welfare state became able to out-vote its net contributors - which has already happened in the US.
> make sure old people don't starve
If only that were what the extent of what social security actually does. But it's not properly asset tested. So broke millenials are paying a ton of payroll taxes, which are - after substantial adminsitrative overhead - transferred to their elders who almost always have significantly more assets than they do, and often don't even need a transfer at all, let alone as their only way of avoiding starvation.
One, your numbers for "already happened in the US" are at best erroneous. The question of who gets what from labor is complicated, but the one thing for sure is that there are no easy answers, because labor itself is deeply social.
Slavery was not fully eliminated in the US; it was just fractionalized, and the terms - which groups are enslaved, which groups are entitled to their output, and how much of it, etc - were obviously heavily modified. For instance you are able to change employers now, but no matter which one you pick - even if it's your own firm - in most highly-valued fields 40-70%+ of your output will be taken by various layers of government - by force if necessary. Your children are subject to the same obligation so "fractionalized chattel slavery" is a decent first-order description.
It is true that acts of extreme violence are less common than they were in the 19th century South, but that alone does not make the system "not slavery" given that a threat of overwhelming force still underpins it.
> It's not legal for Americans to completely avoid taxes simply by operating in a jurisdiction with different tax laws.
This is not correct, and pretty much all of the US Elite, above a certain wealth level, have some offshore structure(s), because there actually are major, legal benefits - including ones that can zero out the US individual tax liability for that activity, at least in some years.
As a result it's only the legally- & financially- relatively unsophisticated middle classes, and perhaps the lower-upper-class, that has literally every single transaction subject to US taxation.
If the untoward event is solely in USD, perhaps, but not if it's in crypto. Exit scams, hacks, rogue employees, etc, could still hit a US exchanges' crypto holdings and the government probably cannot or will not compell a roll back, supply expansion, etc, on a major blockchain.
If anything is actually protecting clients against crypto theft, it's the exchange's privately-purchased insurance rather than the government. Although I wouldn't rely on that for much either as insurers are rarely eager to pay out.
I believe they valued at time-of-transaction. e.g. if you had no other transactions except for a $100 buy in 2013 that you immediately withdrew to personal cold storage, and then that appreciated to $20k+ today, you shouldn't have been included, assuming they supplied only the minimum amount of info legally required.
It doesn't necessarily tax everything but the IRS does seek God-level knowledge/insight into every transaction - and then it just exempts certain things based on size or other factors. If you are deducting charitable contributions to the church they actually do expect you to subtract out the value of coffee, meals, etc. Donate $100 to some non-profit that sends you a t-shirt as a thank-you? Your deduction is $87, not $100, because the t-shirt has to be valued at $13 or something similar that they consider reasonable. Somewhere they actually have federal employees tasked with determining this year's acceptable minimum value for a t-shirt.
The $20 gift from grandma is exempt, but not because they don't demand insight into intra-family transfers.. it's only non-taxable because of its size. If you have a rich grandma and she gives you $20k, that needs to be reported.. even if no tax is ultimately due, it probably reduces the future value of her estate tax exemption. Dying is a very complex taxable event!
If you want to follow the thousands of pages of rules to the letter - sufficient to sign a letter declaring under penalty of purjury, etc - the tracking and compliance burden on many US taxpayers is enormous, even with assistance from the commercial closed-source SW packages that you are more or less forced into buying each year because they won't let you e-file with them directly over HTTPS+JSON or whatever.
AFAICT the risk/reward for this change (and others along the same line) is poor, because like it or not, as a factual matter, there are many tens or hundreds of millions of notionally "open source" devices that will never get an updated Linux/BSD/... kernel. Most of them are probably Android phones but there is also a giant tail of consumer routers, EOL'd network equipment, etc. A lot of this stuff will stay in use until total HW failure, which may be a decade, two decades or more.
There are of course also many closed-source products that will never get a TCP/IP stack update. I haven't tested it but I doubt Win7 will ever be able to reach 0.1.2.3 over the public internet. Even if that's a bogus example, you get the idea: millions of dollars worth of old closed source gear out there where it's impossible for the owner to patch the TCP/IP stack.
As a result, to prevent strange connectivity problems on 0.X% of their connections, almost everyone will pay (and, if needed, significantly bid up) the ~$20/yr "normal" IPv4 address cost to get an existing "non-reclaimed" IPv4 address instead of taking a gamble on one of these new ones that will definitely have problems with many other hosts. In short I don't see a voluntary rational buyer or user until the IPv4 market rises 10X+ and probably more like 100X+; until then they seem like more of a liability than an asset given how annoyingly long it will take to retire (or somehow otherwise ensure that you'll never need to talk with) non-updatable IPv4 hosts.
Not that I like this, or am trying to defend or justify it, but I think it is an accurate assessment.
TLDR: pretty much everyone will actively avoid these addrs given that millions of hosts will never be able to reach them.
This is not a complete, imperfect, optimal, uncontroversial or always-trivial-to-implement list, but some common ways to increase attacker costs are to:
0. Put a CAPTCHA on expensive/abused functionality.
1. Rate-limit costly transactions to 1 per hour/day/etc (whatever's appropriate) per IPv4 address.
2. Limit total amount of data added to the db per time period per IPv4 address.
3. Iff you get a lot of abuse from VPS/cloud providers, block or even-more-severely-limit their published IPv4 ranges. Generally speaking a normal user will not write to a pubkey db from a cloud IP.
4. Iff you get a lot of IPv6 abuse, either go IPv4-only (no doubt this will make some people super-mad.. but when it's the only way to keep the service operational..). Sometimes treating every /64 as roughly equal to one IPv4 address is a sufficient defense.
5. If you don't like using IPv4 as the scarce good, then use some other primitive such as SMS verification of a phone number (that may be unacceptable for sks due to obvious privacy and highjacking concerns.. but it's basically what Signal does..)
6. Users (and environmentalists) will hate it, but if all else fails, require proof-of-work/hashcash. Periodically expire keys that didn't submit a $1-10 POW ticket each year, etc. Or an equivalent minable cryptocurrency payment.
The solution there is to have the app use line buffering rather than a "raw" term mode that exposes inter-char timing on the network. How widely that's followed in practice, I do not know, but one would certainly hope that sudo does it.
If you really cannot use keys, then one mitigation is to use copy/paste to paste the entire password instead of typing it one character at a time. That can open some copy/paste vulnerabilities e.g. in X11 where any app can then read the password until you copy something else in its place. And a network observer may still determine the password length. But it closes the inter-key timing channel that permits direct character recovery.
The "high taxation is not slavery, because you voted" argument lost all merit once net recipients of the welfare state became able to out-vote its net contributors - which has already happened in the US.
> make sure old people don't starve
If only that were what the extent of what social security actually does. But it's not properly asset tested. So broke millenials are paying a ton of payroll taxes, which are - after substantial adminsitrative overhead - transferred to their elders who almost always have significantly more assets than they do, and often don't even need a transfer at all, let alone as their only way of avoiding starvation.