So far, the Reddit contributor program is limited to users in the United States (to start, at least) who are over the age of 18 and can verify their identity via Persona and Stripe.
Guys, here's the real reason. So they can positively identify you. Evidently this is how much that knowledge is worth. They can probably then start selling your posted data to other companies that have also "verified" you via Persona and Stripe. Once those datasets start getting linked together, well I will let your imagination run with that.