"#Sarahah bills itself as a way to “receive honest feedback” from friends and employees. But the app is collecting more than just feedback messages. When launched for the first time, it immediately harvests and uploads all phone numbers and email addresses in your address book. Although Sarahah does in some cases ask for permission to access contacts, it does not disclose that it uploads such data, nor does it seem to make any functional use of the information."
https://theintercept.com/2017/08/27/hit-app-sarahah-quietly-uploads-your-address-book/