messaging 1. An e-mail message containing live data

intended to do nefarious things to the recipient's computer or

terminal. It is possible, for example, to send letterbombs

that will lock up some specific kinds of terminals when they

are viewed, so thoroughly that the user must turn the terminal

off to unwedge it. Under Unix, a letterbomb can also try to

get part of its contents interpreted as a shell command. The

results of this could range from silly to tragic.