Under What Conditions Would It Be Professionally Acceptable to Use

Under what conditions would it be professionally acceptable to use resources that are "anonymous"?

A) when the accounts are associated with some sort of organization or foundation
B) when you already know who "anonymous" is
C) when the accounts have a "ring of truth" to them and seem logical
D) when you wish to examine first-person accounts dealing with sensitive personal issues, like descriptions of abuse or sexuality