The METW and MELE rules restricting the "play" of corruption cards do not mention "placing" of corruption cards. First, note that the METW corruption cards are not "played" on a character (they just give corruption points to a target character), whereas the corresponding MELE corruption cards are "playable on" certain characters. So maybe we should give this rule some leeway.
Second, the ICE Netrep did not see any difference between "playing" or "placing" a corruption card on a character: of course Morgul-knife may not be "placed" on a character if Lure of Nature was already "played" on them that same turn.
So a corruption card may not be played on a character that had Icy Touch placed on them that same turn.