[Archived] ASP.NET Core Identity is the membership system for building ASP.NET Core web applications, including membership, login, and user data. Project moved to https://github.com/aspnet/AspNetCore
Because some people use those logs to monitor for attacks. Hence it's a warning that something you might want to look at is happening. It won't change.
In my opinion this should be an Information level warning. What is the reason behind a Warning level here?
https://github.com/aspnet/Identity/blob/c7276ce2f76312ddd7fccad6e399da96b9f6fae1/src/Core/UserManager.cs#L711