I have never actually seen any sort of cogent response to this issue. Ever. I see it being brushed aside constantly, along with the magical brain restoration technology necessary for this, but I've never actually seen someone go into why, exactly, anyone would bother to thaw them out and revive them, even if it WAS possible to do. They are, all for all intents and purposes, dead, from a legal, moral, and ethical standpoint. Not only that, but defrosting them has little actual practical benefit - while there is obvious value to the possible cryopreservation of organs, that is only true if there aren't better way of preserving organs for shipment and preservation. As things are today, however, that seems unlikely - we already have means of shipping organs and keeping them alive, and given the current trend towards growing organs, it seems far more likely to me that the actual method will be to grow organs and keep them alive rather than keep them in cryopreservation, and without that technology being worked on, there is pretty much no value at all to developing unfreezing technology.

That means that, realistically speaking, the only purpose of such technology would be, say, shipping humans to another planet, which while probably not really rational from an economic perspective is at least somewhat reasonably likely. But even still that is a different kettle of fish - the technology in question may not resemble present day cryogenics at all, and as such may be utterly useless for unfreezing people from present-day cyrogenic treatments. Once you can prove that people CAN be revived in that way, then there is much more incentive towards cryogenics... but that is not present day cryogenics, and there is no evidence to suggest future cryogenic treatments will be very similar to present ones.

Okay, so even all that technology aside, let's assume, at some point, we do develop this technology for whatever reason. At this point, not only do you have to bear the expense of unfreezing these people, but you also have to bear the expense of fixing whatever is wrong with them (which, I will note, actually killed them in the past), as well as fixing whatever damage was done to them prior to being cryogenically frozen (and lest we forget, 10 minutes without oxygen is very likely to cause irreparable brain damage in humans who survive - let alone humans who are beyond what we in the present day can deal with). This is likely to be very, very expensive indeed, and there is little real incentive for someone in the future to spend their money in this way instead of on something else. You are basically hoping for some rich idiot to not only be capable of doing this, but also being willing to do it and having the legal ability to do so (as, lest we forget, there are laws about playing around with human corpses, and I suspect that it is unlikely they will change positively for frozen people in the future - as if they do change, what are the odds that your frozen body won't be used in some other sort of experiment?).

I have never seen arguments which really address these issues. People wave their hands and talk about nanotechnology and brain uploading, but as someone who has actually dealt with nanotechnology I can tell you that it is not, in fact, magical, nor is it capable of many of the feats people believe it will be capable of, nor will it EVER be capable of many of the feats that people imagine it will be capable of. Nanomachines have to be provided with energy the same as anything else, among other, major issues, and I have some severe doubts about the unfreezing process in the first place due to various issues of thermodynamics and the fact that the bodies are not frozen in a setup which is likely to facilitate unfreezing them.

A lot of cryonics arguments basically boil down to "future technology is magic", and that's a pretty big problem for any sort of rational argumentation. "You can't prove that they won't be able to revive me" can be used for all sorts of terrible arguments, as the burden of proof is on the person making the argument that it IS possible, not on the person holding to the present day "we can't, and see no way to do so."

I mean, you look at things like:

http://www.alcor.org/Library/html/resuscitation.htm

The technology in here is, quite literally, magic. It doesn't exist, and it won't exist. Ever. Things on the level are very dumb; they cannot be intelligent, and they cannot act intelligently, because they are too small, too simple. The bits where they stick stuff into your cells is where things get really ridiculous, but even before then, those little nanomachines are going to have real issues doing what you are hoping for, and would have to be custom built for the task at hand. We're talking enormous expense if it is even possible to do at all, and given the extremely small cryogenic population, the odds of perfecting the technology prior to running out of dead people is not very good. Remember, if the result is brain dead or severely brain damaged, it is still a failure. But even these sorts of nanomachines are very questionable; transistors are only going to get 256 times smaller at most, which makes me question whether said nanomachines can function in the way that is hoped for at all. Of course, this is not necessarily a barrier to, say, a different sort of nanomachine (though they'd be more micromachines really, on the scale of a cell rather than on the scale of large molecules) which was controlled by some sort of external process with the little machines being extensions/remotes of it, but this is still questionable.

Extreme expense, questionable technology (which would have to be custom developed for the purpose), the question of whether cryonics is even a viable technological route for something else for cryogenic revival to piggyback on, likely custom technology for reviving people who have died of things that people no longer die of because of earlier preventative measures (why build something to fix someone with late stage cancer when no one gets late state cancer anymore?), legal problems, the necessity for experimental subjects... all of these things add up to the question of why these hypothetical future people are even going to bother. That's assuming it is even ethical to revive someone who is, say, not genetically engineered and therefore would be at the bottom of the societal heap if they were revived.

Dunning-Kruger

You obviously have not actually read the Dunning-Krueger paper and understood what it showed.

and experience with similar religious movements suggests otherwise.

Name three. Like V_V, I suspect that for all that you glibly allude to 'cults' you have no personal experience and you have not acquainted yourself with even a surface summary of the literature, much like you have not bothered to so much as read a cryonics FAQ or book before thinking you have refuted it.

It takes someone who really thinks about most things very little time to come up with very obvious objections to most religious doctrine

And it takes even less time to notice that there are long thorough answers to the obvious objections. Your point here is true, but says far more about you than religion or cryonics; after all, many true things like heliocentrism or evolution have superficial easily thought-of objections which have been addressed in depth. Sometimes they work, sometimes they don't; the argument from evil is probably the single most obvious argument against Western religions, there are countless replies from theists of various levels of sophistication, and while I don't think any of them actually work, I also don't think someone going 'My mother died! God doesn't exist!' is contributing anything whatsoever. What, you think the theists somehow failed to notice that bad things happen? Of course they did notice, so if you want to argue against the existence of God, read up on their response.

Which is more likely - that people are deluding themselves over the possibility of eternal life and don't actually have any real answers to the obvious questions, but conveniently ignore them because they see the upside as being so great, or that this has totally been answered, despite the fact that you didn't even articulate an actual answer to it in your response, or even link to it?

If you had spent less time being arrogant, it might have occurred to you that I see this sort of flip reaction all the time in which people learn of cryonics and in five seconds think they've come up with the perfect objection and refuse to spend any time at all to disconfirm their objection. You are acting exactly like the person who said, "but it's not profitable to revive crypatients! QED you're all idiots and suckers", when literally the first paragraph of the Wikipedia article on ALCOR implies how they attempt to resolve this issue; here's a link to the discussion: http://lesswrong.com/lw/gh5/cryo_and_social_obligations/8d43

Notice how you are acting exactly like cheapviagra. You've come up with an obvious issue for cryonics, and rather than do any - gasp! - research; you commented on it. OK, fine. I then told you that there were replies to the issue, and that you should've known this because the issue is so obvious, and rather than learn a lesson about useful contributions, you are instead self-righteously criticizing me for not willing to drop everything and dig up every answer to every idle passing thought you have!

By the way, a benchmark I've found useful in discussing factual matters or matters with a long pre-existing literature is number of citations and hyperlinks per comment. You're still batting a zero.

I'm pretty sure that, historically speaking, the former is far more likely than the latter.

I'm impressed you've failed to notice that LW is maybe a little different from other sites and we have higher standards, and what happens 'historically' isn't terribly relevant.

The fact that you did not have a counter for my argument and instead linked to a page which was meant to be a "take that" directed at me is evidence against you having an actual answer to my query, which is always a bad sign. This is not to say that it doesn't have an answer, but a quick, simple answer (or link) would be no more difficult to find than the litany article.

Apparently you missed the point. The point was: stop being arrogant. Think for a freaking second about how obvious an argument might be and at least what the reply might be, if you cannot be arsed to look up actual sources. Do us the courtesy of not just thinking your way to your bottom line of 'cryonics sucks' but maybe a step beyond that too.

Indeed, after looking at the Alcor site, and reading around, all I really find are arguments against it. The best argument for it that I've seen is that resurrecting 20th century people might be profitable from an entertainment/educational standpoint

Really? That's the best argument? What did you read, exactly? Where do they say 'there's no reason to revive people except for entertainment'? Or are you just picking out the weakest possible argument because that's what you want to talk about?

As ciphergoth pointed out, there isn't really a good answer here.

What? No! That's not what ciphergoth meant at all! Here is what he said:

And it's not necessarily that the replies to this problem are good, but that they are what you need to reply to.

He did not say the answers were not good. He said, that even if the answers were not good, they are still what you need to deal with. You need to work on your reading comprehension if that's what you got out of his comment. (Shades of Dunning-Kruger, since you brought it up...) Or is this another aspect of you refusing to do any research, bring up the weakest lamest arguments you can find as strawmen, and grossly misinterpret what people have said?

I was reading one article on Alcor which suggested that, even for a cyronics optimist, the odds of it actually paying off were 15% if he only used his most optimistic numbers - and I think his numbers about the technology are optimistic indeed. That's bad news,

No, it's not bad news. It's just news. Expected value is about payoff, cost, and probability. 15% means nothing more and nothing less than 15%; without additional details, it does not mean that something is a good idea and it does not mean something is a bad idea either.

gwern's interpretation of what I wrote here is entirely correct.