Off the top of my head I can't speak to Facebook's program, but Google's terms include "substantially affects the confidentiality or integrity of user data". A login page that shouldn't be exposed is a marginal finding and might not qualify.

Also: obviously I don't speak for either Facebook or Google, but I strongly recommend against brute-forcing login prompts to try to prove the point that an exposed console is a real finding.

"Report a bug that could compromise the integrity of Facebook user data, circumvent the privacy protections of Facebook user data, or enable access to a system within the Facebook infrastructure"

^That's Facebook's. Theoretically, an exposed login page "could...enable access to a system within the Facebook infrastructure", but to be fair, I doubt they had that in mind.