What did the court decide in Neitzke v. Williams?
Answered for: US
We therefore hold that a complaint filed in forma pauperis is not automatically frivolous within the meaning of § 1915(d) because it fails to state a claim.
The Court distinguished the in forma pauperis frivolousness standard from the Rule 12(b)(6) failure-to-state-a-claim standard. The sentence above is the court in its own words.
This answer is true in US and nowhere else on this site. Another jurisdiction is another answer, or an honest gap: see what has been read for US.