By chance I searched for Stripe Secret API Keys (using this regular expression sk_live_\w+) and found that there a few sites exposing keys in publicly available source code.
These secret API Keys let anyone access a full list of the business's customers' information, including names, emails, credit card types/last4, and other related banking information.
Always consider exposed keys as compromised. I wonder how long they have been live and public.
https://nerdydata.com/search?regex=true&terms[]=sk_live_%5Cw%2B
https://nerdydata.com/search?regex=true&table=jsfiles&terms[]=sk_live_%5Cw%2B
https://nerdydata.com/search?regex=true&table=deepweb&terms[]=sk_live_%5Cw%2B