Infant baptism strikes me as worse.
So would you encourage anyone who remains Christian who was baptized as a baby to be rebaptized? I guess you'd approve of me "invalidating" my infant baptism by getting rebaptized in a few weeks.
"Invalidating" Baptism? Dude, it's a Sacrament. Either that charade your parents went through when they had you baptized as an infant was not a Sacrament at all but a mockery of one (and thus probably blasphemous to boot; not consciously of course, not saying that at all), and then there is no reason to bother with invalidating though you do need to be rebaptized; or it's valid anyways and you can't invalidate it (though I guess you could still be rebaptized just for, you know, yourself and the world, rather than God).
While I've heard of errors of ritual "invalidating" a Sacrament, I've never heard of some kind of "invalidating ceremony". That seems to be an innovation to Christianity quite as strange and disturbing as anything the Mormons come up with.That's a very Catholic-centric view (as well as from afleitch), evidenced by use of the word "Sacrament", some Protestants use it yes but most that baptize only adults use the term "ordinance" instead. Though "invalidate" was a poor word to use.
Protestant churches that don't baptize babies still have a dedication ceremony for them, mine is doing it the same day I'm being baptized. So the view is that infant baptism is not an actual baptism, just equivalent to a dedication except using water. People who were baptized as babies therefore were merely only dedicated and can grow up and decide to be baptized if they wish (like I am), and if they aren't they baptized again it's not a big deal since baptism is only symbolic in most's view and not required for salvation (unless you're talking to some very legalistic cult-like groups and some extreme Pentecostal sects even other Pentecostals consider crazy.) A person who was baptized/dedicated as a baby and does not grow up to be a Christian has no need to "invalidate" their baptism/dedication since it was only symbolic and had no real effect on them, granted many would believe that any such person would be damned but that's due to rejecting Christ, not failure to carry out some bureaucratic ritual. And if a person actually is baptized as an adult but then backslides anyway most simply hold then the baptism wasn't valid (or if it's done against the person's will, or if the person is not a believer but does it for other reasons), meaning there is no need for an "invalidation". afleitch may not be able to "anull" his baptism as he doesn't plan on getting baptized in another church, but to a non-believer it's a pointless ceremony anyway, so why bother? Most Protestants also would consider that he effectively "annulled" it in his lack of belief, which is what I would say as well. (No the Catholic Church doesn't because they do believe that it leaves some sort of "indelible mark on the soul", but that's moot to a non-Catholic believer. As far as I'm concerned as well as him it was just some guy sprinkling water on a baby's head.)
My pastor when speaking of baptism said that if you were baptized as a baby and are fine with that so is he (since his policy on arguments is "don't have them".), so he clearly doesn't consider infant baptism blasphemous. Neither does
this church which actually agrees to baptize babies if the parents wish (when signing up for that they are given a choice of infant "baptism" or "dedication"), but also baptizes adults including those baptized as babies and shows an obvious preference as to which they prefer if you watch the videos at the bottom (note Krysta's). So baptizing babies to them is sort of mildly discouraged, but obviously not banned or considered blasphemous.
If there's something I would consider blasphemous, it's the view that God would condemn someone because their parents neglected to carry out some ordinance/sacrament or because their ancestors didn't do it for them either in the future, or essentially any "bureaucratic God". The former view isn't too common in Catholicism any more (though still is held by some radically conservative Lutherans and Calvinists), but the latter in Mormonism is actually the only thing I find offensive in their proxy baptisms.