Best case, this is a well meaning project by someone that doesn't understand the implications of sharing secrets. Unfortunately it could be a ruse to harvest api secrets from people that don't understand the implications of secret sharing.
EDIT:
In the case of Stripe keys, I wonder if it's a strategy to bypass Stripe's "carding" detection? It seems like spreading out test transactions across multiple stripe accounts would make detection more difficult.
A couple of dashboard screenshots:
Stripe key collection:
https://i.imgur.com/q6evqlT.png
Plan Upgrade:
https://i.imgur.com/nwBZ2wL.png
EDIT: In the case of Stripe keys, I wonder if it's a strategy to bypass Stripe's "carding" detection? It seems like spreading out test transactions across multiple stripe accounts would make detection more difficult.
https://stripe.com/docs/card-testing