They'd have to be very motivated “vandals”, though. (More like people with an agenda than bored/frustrated people the word vandals usually suggests to me.)
If I have N% confidence that continuing to cryopreserve a particular mass of brain tissue will ultimately cause person X to experience Y QALYs, then presumably the value V of continuing such cryopreservation to me is roughly equivalent to the value of N*Y QALYs for X. If I believe Y is very large and N is not offsettingly small, and I significantly value QALYs for X, then presumably V is larger than the value of large sums of money.
In other words, the extortion potential here is enormous. Some people are motivated by that sort of thing.
Potentially of interest to my fellow antipodean LessWrongers. Stasis Systems Australia is a company seeking to start a cryonics facility in Australia. Their website is pretty sparse, but they just sent out a mailing list update on how they are going, and it doesn't appear that the information therein is located in any news section of the website, so I thought I'd post it here.