Caller ID just says "Out of Area"; called at 8:00 AM -- I promptly blocked it.

I hope that soon most people will have the capability to block unwanted calls so that there's no profitability in doing this any more.

Always ask for accounts payable.  Will never leave a message when I tell them they're unavailable and never leave a voicemail.  If i tell you, "Can i take a message?" and you always say no, then that's a pretty good sign you're trying to sell/scam something.

Harassment.

Got a phone call from this number that says GE Capital.  Answered the call and it's music playing saying that I'm on hold and that the call may be recorded.  Asked me to wait to be connected to next available person.  Are you serious?  Don't call our business line and put the person you called on hold and have them wait.  Telemarketers are just getting lazy now.

Called and leaves no message.