Maybe you should work on making your contract law more trustworthy then, if you think corporations can just randomly decide to extort your family years later.
Kinda hard to ensure it keeps being trustworthy after you're dead.
Also, who said it was random? What if they simply run out of money, for any of the hundreds of reasons why companies do? Laws can't magically force them to keep it running if they literally can't afford to.
All I'm saying is that these scenarios can be sufficiently covered by contracts with the institute you want to preserve you. You can specify that in the unforeseen event of needing more funds to keep you preserved, that you are terminated and buried or cremated in such-and-such fashion without even trying to seek funds from potential relatives or descendants or the government. If contract compliance trust is an issue in Europe, that seems like something to fix first.
It doesn't matter how the contract compliance law works now; it matters how it'll work 20, 40 or 60 years after you're dead. How can you be so sure that a law won't be passed giving the right to the family to override those clauses?
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.
