The following calls require a user to be logged in:

/api/json/reviewrequests/all/
/api/json/reviewrequests/to/group/<group_name>/
/api/json/reviewrequests/to/user/<username>/
/api/json/reviewrequests/from/user/<username>/
/api/json/reviewrequests/repository/<repository_id>/changenum/<changenum>/

Why? You can get this information without a login using a web browser, why
is there a login requirement to fetch the data using the API? Can these
calls be modified to not require a login?

Thanks.