[greendragon]

Contract law has had a good run so far, I expect it to continue to have one unless we kill all the lawyers. Even then the concept of a written will is very old.

Maybe I should rephrase my overarching point since it seems to be lost in the details. Concerns over scamming by exploiting family or in general not doing with your remains what you wanted to have done ought to be the least of one's concerns when making a decision on cryonics, unless there's a serious problem with contract law in Europe. I believe Alcor won't even accept you unless you have an official, legal will about it, precisely to defend against family members overriding your decision, since case law on upholding wills is pretty solid. That suddenly changing in 20-60+ years seems pretty unlikely. There are bigger threats to spend more time modeling. Even proponents only estimate around a 5% chance of successfully being revived, were they suspended today (see http://www.overcomingbias.com/2009/03/break-cryonics-down.ht...). I don't think anyone who is signed up thinks they have a sure shot at revival, let alone dying in a convenient enough fashion to be usefully preserved, and the two big cryonics orgs in America certainly don't market it that way. The calculation usually goes that for a modest monthly payment on a life insurance plan covering ~$80k, you have a small chance of cheating death, versus having no chance (barring truly magic-like powers like reconstructing you from others' memories/dna/browser history/etc.) if you die and get buried or cremated the normal way.