It's playing a game when one uses it as an excuse to not respect the other party in a charitable discussion. That is, you don't need a source if you accept that

It's playing a game when one uses it as an excuse to not respect the other party in a charitable discussion. That is, you don't need a source if you accept that the other party is acting honestly in the discussion. Asking for sources so that you can examine the data yourself is admirable. Asking for sources because certain words "trigger red flags" for you that the other party is not acting in good faith is a different problem. "In philosophy and rhetoric, the principle of charity requires interpreting a speaker's statements to be rational and, in the case of any argument, considering its best, strongest possible interpretation."