There is no 'rule' that says you can't and if someone does get angry, it will be another resort guest not a CM, and if that's the case, getting angry over your wreath is their problem not yours, AND if that makes them angry then they have no business being at Disney at Christmas. We're there at the same time .... send the angry person to me

HA!
As for someone swiping it .... karma means as they run off, they will drop the wreath, their foot will get tangled in it, they will crash to the floor as I happen to be on the way to the food court and I will point and laugh
Sorry. I can be ever so naughty sometimes
EDIT: I saw on the POR board back in January pictures of wreaths & door decorations