I'm not arguing that sour candy is good or bad. I certainly don't enjoy it. However, this garbage posted to Kottke (Kottke has an update which is a bit better) and BoingBoing is just inflammatory abuse of science. pH is a log scale. So to say sour candy is like battery acid is like saying the moon is about as far away as the sun.
I'd also point out that the scale used does not go low enough. Battery acid pH is significantly lower than one. But since it's a log scale, rounding to the nearest non-zero whole integer places it at one. Seriously, according to these arguments, lemon juice is more acidic than sour candy so that must mean it's more acidic than battery acid.
Maybe a little research before trying to freak people out.