This really gets my goat. Just having my number is one problem. Handing out willy-nilly to anyone who asks for it is unethical. Unfortunately, no one seems to really care in India. Everyone wants the comfort of knowing who is calling them. Blocking telemarketers seems to be high on the priority list.<p>This is frustrating for someone who is developing an address book app. I cannot believe that people keep asking us to provide 'truecaller' functionality! I even have a one-star review on the app store because I don't hand out numbers like these apps do. I have seen some other apps gradually given in and add this functionality because of user pressure.<p>In short, the apps are probably doing it because they are afraid of losing users and hence money.