I registered for this and I am in line. To get prior access. I am asked to refer my friends. Just wondering how robinhood shows all my friends though I have no

I registered for this and I am in line. To get prior access. I am asked to refer my friends. Just wondering how robinhood shows all my friends though I have not connected robinhood to any of my social network. I feel this as a big privacy issue and it’s concerning a lot.