Posted By:
warshawlaware dirty old men 
I think we need to be very careful not to hijack the question. I read the initial inquiry as a more or less philosophical question. I can see reasonable people differing philosophically on whether a card "should" be soaked to remove paper or paste. Some want cards to remain as they are found by collectors and never altered. Others figure that if the card is found stuck to an album page it has already been altered and removing the paper isn't "wrong" because you can't mess it up any worse. I don't think there is a "right" answer to the philosophical question, just opinions.
I think what is rubbing some folks the wrong way is that the philosophical question naturally leads to an ethical and possibly legal question as to whether it is ethical/legal to soak a card off the sheet, have it slabbed, and offer it as such without disclosing the bath it took. While I personally may be fine with the practice of soaking and pressing a card to remove paper stuck to it and would like to see conservation of cards treated the same way as conservation of artwork, in the current climate, ethically and legally it raises many problems. It is just too easy and too lucrative to buy a damaged card, remove the extraneous material, and have it slabbed, thereby certifying to the world that it is unaltered (I know, I know, the slabbing emperor has no clothes, so to speak, but that is for another thread).
Perhaps the solution we are ultimately working towards is for the slabbers to agree that when a card is slabbed it means that it may have been conserved (properly cleaned) but isn't altered (added to).