I always think about it twice when I need to put my telephone number.
It seems too easy to me to start being bombarded with texts messages and so hard to stop them.
It also seems quite easy to start subscribing massively telephone numbers with a simple script (I hate captchas but I understand why they're in the game).
This sentiment makes sense, we have a few safeguards in place right now, but we wanted to open this feature up to people who might not already be using the app and telephone number felt like the best way.
We will have a think about a better way to implement this.