I've noticed a certain dissastifaction with the vague messages medical professionals sometimes leave on phone machines. I asked about this a while ago, when a particular message was particularly vague (which doctor, dammit??), and found out the reason.
They're trying to protect your privacy. They don't know who might actually receive the message, so intimate details, numbers, whatever, will not be left on a phone message. While I have a problem with the necessity of this, I have to agree with it. Yes, it's unnerving to be told something may be wrong w/o being told what and why, but the alternative could be that your SO finds out you've been cheating, or that your roommate might get details you don't want him/her to get.
Fun stuff, huh?