What risks are there in using an OAuth2 access_token from an IdP that I do not control to secure an API that I do control?

Imagine I host some API. Its exact function is irrelevant to the question, but it needs to have some sort of authorization put in front of it. I want to call Google’s APIs, so users can interact with their Google data, so I add the necessa… Continue reading What risks are there in using an OAuth2 access_token from an IdP that I do not control to secure an API that I do control?