Well, I found Anne's link http://www.harrypotter-xperts.de/index.php?pa...
to be a real eye-opener. I've heard Germans bemoan poor translations of novels, but seeing examples really brings the problem home.
Sometimes entire sentences were simply left out, other times phrases were added for no apparent reason. And here are just a few of the outright howlers from the second book alone:
plugs --> Pflüge
purple --> purpurrot
custard tart --> Senftorte
got to his feet --> warf sich in die Brust
dead ends --> lose Ende
Apparently the first German translations were done under considerable time pressure. Nevertheless, mistakes like that hint pretty strongly at not just haste but a lack of care and/or competence.
So as far as I'm concerned, if readers want to get together and improve upon stuff like that, more power to them. Sure, the 4-day version is bound to be rough, but it's probably only intended for basic comprehension. And ideally, the longer-term critiques should be an impetus for the German publishers to provide better translations (by, for instance, paying enough to attract better translators, and giving them more time and better editorial support).
Obviously, hoping that individual readers can influence anything as monolithic as the publishing industry is often wishful thinking. But with the HP books, would German speakers agree that the published translations at least seem to have improved over the course of the series? If so, the various reader-led online initiatives may have had the desired effect.
In any case, I agree with Nicole that it seems petty to sneer at anything that encourages people, particularly young people, to read and think analytically about language.