Why pick that particular occasion to make the protest, rather than, say, someone buying a speedboat?
Off the top of my head, that someone is interested in cryonics is very strong Bayesian evidence that they'll be easier than average to persuade to donate to SIAI. On the other hand, this would equally justify suggesting to them to cut back on other luxuries to donate. But like Michael Vassar suggested and I elaborated on, since the benefit of cryonics is far-off and uncertain, it may take less willpower to give up than other luxuries. But surely not that much less...
(As you might guess, I'm currently trying to make this decision for myself.)
I hate to suggest it of high-caliber rationalists, but I wonder if the decision to forgo cryonics might be sometimes partly motivated by conspicuous self-sacrifice signaling, or even if the altruistic justification is sometimes partly a rationalization for forgoing cryonics in favor of other luxury goods.
...on signing up for cryopreservation with the Cryonics Institute.
(No, it's not a joke.)
Anyone not signed up for cryonics has now lost the right to make fun of Paris Hilton,
because no matter what else she does wrong, and what else you do right,
all of it together can't outweigh the life consequences of that one little decision.
Congratulations, Paris. I look forward to meeting you someday.
Addendum: On Nov 28 '07, Paris Hilton denied being signed up for cryonics. Oh well.