This is just me, but I tend to eyeroll (privately) when people wig out about others touching their cards. One casual finger-brush is apparently enough to upset the balance of energies and require a full cleansing. It's like they think everyone is covered in psychic germs or something. Rude.
On the other end of the spectrum are those who feel free to do anything with your deck without asking. This only happened once, but I had a roommate "anoint" my deck with some foul-smelling oil, because she had just done her own and had some extra oil on her hands. My deck is not your hand towel, missy!