Question: I was testing my login/sign up feature and for some reason I can't understand Firebase now is blocking all requests from my device.

I've waited one day to try again, but I still have the same problem.

> 
> ERROR:
>  "We have blocked all requests from this device due to unusual activity. Try again later."
> 
> 
> 

What should I do to have access to my database again?

Answer: 
One of the possible solutions: 

1. Go to your Firebase console -> Auth -> Users table
2. Locate the user you are testing.
3. Delete this user.
4. Retest.
This is one of many quirks that I am running into. While Firebase seems to be a nice framework/product/service, at the moment it doesn't seem to be totally ready for broad production deployment yet. In this case I only used one particular (fake) user for testing/debugging and only after just a few attempts (probably no more than 10 sign-ins), I ran into this issue. The funny thing is that my tests delete the fake test-user after each run so I couldn't see any user in my auth user table afterwards. The solution for me was to manually add that user via the "ADD USER" button and then delete it. I think they should have (at least as a workaround) a definable user that is for testing/debugging, who is not subject to this restriction, if they really feel they have to have such a (low) limit.