It never ceases to amaze me...
Just how quick people are to trust and not question communication. If a stranger walks up to you and tries to convince you of something most often you have *some* level incredulity until they identify themselves in some way. But when it comes to phone calls, mail, and email people are largely defenseless. Even then one simple bit of information is usually enough to disarm those who are leery. Oh, they know my bosses name, what equipment we use in the office, or they used an official looking letterhead/graphic.