I was watching a random cop program and one of the protagonists needed information on where the person she was hunting was. She called the office, pretended to be the firm detailing his car and got the information she needed.
When I was a recruiter, one of my jobs on a Thursday was to get the local paper and call all the other agencies trying to find out which clients of theirs were hiring. You’d be amazed what people will tell you, without you having to tell any lies, just by using a pleasant voice. I called a business locally recently and asked for someone, only to be told he was in rehab. I didn’t even give my name.
There’s two lessons to this. One, if you need to know something, just ask. You’ll probably get the answer. And two, if you get random calls from people with pleasant voices, find out who they are and what they need to know before you give away confidential information.