Wildly off base. The key steps are whether on a molecular level, no more than one original person has been mapped to one frozen brain; if this is true, we can expect sufficiently advanced technology generally, and systems described in Drexler's highly specific Nanosystems book particularly, to be sufficient albeit not necessary (brain scanning might work too). There's also a lot of clueless objections along lines of "But they won't just spring back to life when you warm them up" which don't bear on the key question one way or another. Real debate on this subject is from people who understand the concept of information loss, offering neurological scenarios in which information loss might occur; and real cryonicists try to develop still-better suspension technology in order to avert the remaining probability mass of such scenarios. However, for information loss to actually occur, given current vitrification technology which is actually pretty darned advanced, would require that we have learned a new fact presently unknown to neuroscience; and so scenarios in which present cryonics technology fails are speculative. It's not a question of "fail to disprove", it's a question of what happens if you just extrapolate current knowledge at face value without worrying about whether the conclusion sounds weird. Similarly, you can postulate a social collapse which wipes out the infrastructure for liquid nitrogen production, and a cryonics facility could try to further defend against that scenario by having on-premises cooling powered by solar cells... but if you were actually told the US would collapse in 2028, you would have learned a new fact you did not presently know; it's not a default assumption.