There is a common thing people do in the Q&A after talks/lectures where instead of asking a question, they try to make a point, often using rhetoric and hyperbole in their question to discredit the speaker. And rarely is the question boiled down to something simple, instead a long rambling goes on and (in some cases) baffles the speaker/lecturer who is left to distill the question down to more simple terms. Don't do this!
I've always preferred the format where the speaker or moderator asks for several questions in one round, then the speaker can pick off each question in one go.
This approach puts the onus on the questioner to be as concise as possible, which is not too much to ask in consideration of the audience.
It becomes more difficult to grandstand when the audience recognizes that the objective is to collect a set of questions as quickly as possible and you taking 5 minutes to set your question up is at best tedious and at worst insulting to everyone in attendance.
Often the point they wish to make is "I am very knowledgeable about this subject too" but the point they actually make is "I am jealous of the speaker's prestige." One of the reasons I usually try to sneak out before the Q&A regardless of how good the speaker was...
The social expectation for speakers to tolerate these kinds of questions should be fought. Anyone putting together a lecture and invite a speaker should set the right kinds of expectations - even if it means cutting off the mic
