Isn't it a common refrain at the more paranoid of airports (or at least those where the more paranoid have hijacked the airport PA system) to demand that you notify the TSA or, more useful in this case, the airport police, when asked to transport items by persons unknown to you?
I mean if a bottle of water inevitably results in aircraft disaster, think of the havoc that will evolve if a slip of paper, provided by persons unknown to you, is brought through security.