If you are in Istanbul and you want to use public transportaion with monthly subsrciption you need to buy Istanbul Pass with your ID, it has your name, picture etc. Because you provided your ID they know your birthday. Thus, on your birthdays when you step inside your bus and make your Istanbul Card read by the device (NFC) it says laudly "happy birdthday!". Because all kinds of public trasport use same card, like in ferries, metros, toilets, busses, trams you hear "happy birdthday!" all day in multiple locations.
https://youtu.be/1mJJPID104s
Oh, and you can see from their web sites where you have used your Istanbul Pass in the last few months, like "bus M42 Mecidiyeköy-Bakırköy, at 12:34 Today, -1 credit".
That sounds kinda nice to me, actually. If I see someone going through a turnstile and their birthday is announced, I can shoot them a smile and a nice “hey, happy birthday”.
Little things to invite positive personal interactions between strangers can be a good thing. That is, perhaps, not the intended purpose, but it at least seems like a welcome side effect.
A very unwelcome side effect of that would be that I don't get to control it. It's obviously unnecessary for the service to be performed, but they decide to "invite positive personal interactions" no matter whether I want any of that at that moment in that place.
Oh, and you can see from their web sites where you have used your Istanbul Pass in the last few months, like "bus M42 Mecidiyeköy-Bakırköy, at 12:34 Today, -1 credit".