Today I was contacted by someone at work. She graduated school with me and our 20 year reunion was coming up. Why did she contact me at work? It was the only way they were able to track me down. I was included in promotional material by name. She told me I "was the hardest to track down"and I had to smile.
This is just a small anecdote about privacy practices and their real life impact (and how your employer can undo all of it, I guess)
Then give it to them. Address books, physical and digital, are nothing new.
Some of us don’t want just anyone with something to say showing up in our inboxes.