The right answer to this question is to accept that the company is extracting / harming people. And admit that they didn't stop to think about that when they were building it. That's understandable - they had no idea the impact that facebook would have on society when they were building it.
You can then go on to have a productive collaborative discussion about what to do about it (which isn't obvious or easy). The environment is hostile because Zuckerberg isn't engaging in the process, and is stonewalling congress with "we have a process for this".
He's not being honest, and I suspect (and hope tbh) it will eventually be the downfall of his company.
If the answer is predetermined and known it isn't a question. It is some sort of formal whipping and there is no point giving any answer.
From the peanut gallery it is plausible that Facebook is a net win or a net loss for adolescents and it is possible that the company has a staff psychologist who has actually thought about its impacts. That question is so hard to answer in the negative I seem to have 2 people answering in this comment chain as though the frame is obviously correct and Zuckerberg needs to answer yes then atone for his sins. Public hearings are not the place to engage with these sorts of questions (there might be consequences if he makes a mistake in his answers).
The right answer to "have you stopped beating your wife?" is not "yes" if you don't actually beat your wife.
Similarly, the answer to "did you know the thing you were doing was evil?" is not "no" if the thing you did was not evil. Answering like that is conceding the point.
But they have conceded the point. I think that's why things like Cambridge Analytica were mentioned so many times during the hearing.
Anything you say can and will...
If the person doesn't answer the question, go ahead & berate them. Just don't expect a complicated question to be answered with a simple yes/no.
Likewise it's terrible to judge a politician based on their yes/no voting record without understanding why they voted for/against something.
One example, Ocasio-Cortez asked: Can a politician lie about Election Day on a Facebook ad?
The answer is clearly yes. It isn't complicated.
Or this one: Does Facebook see a problem with its lack of fact-checking capabilities?
How can the answer to this be anything except yes?
Imagine that Facebook is required by law to check every fact in every advert that is on their platform. Is that even possible? Would they have the resources to hire unbiased, critical-thinking people who are capable of doing htat? How expensive is that? Would they just rely on the cheaper option - algorithms.
A friend of mine got banned from Facebook for a month for sharing a meme, posted by somebody else, that had a swastika in it. The meme was of the sort "Nazis were horrible idiots". He appealed the ban, on the grounds that the original post was not taken down (he just shared it) and that this had nothing to do with nazi propaganda. It was, in fact, the opposite. An actual human being looked at that appeal and still confirmed the ban.
What makes you think the process will be any more efficient and rational with political advertising? Relying on companies to police content is absurd in every respect, from freedom of speech rights to just plain capability. There's an entire court system built up with the sole purpose of determining truth and even that isn't 100% accurate. Trust the same responsibility on a corporation?
I'm saying maybe Zuckerberg should acknowledge the nature of his company. Then openly try to fix it.
Now in theory someone asked that could answer without accidentally agreeing that their company is extractive/they are harming young girls/they are recklessly not considering the impacts of their work. Bonus points if they can answer without getting shouted down for not directly answering a yes/no question with a yes/no. Lose a point if the answer gets testy and they look like they are defensive or flustered.
They also have to do that while being completely honest, without getting tongue-tied and correctly assessing the question in a very short time frame.
Zuckerberg isn't a barrister, he didn't found an empire on the ability to think quickly under a barrage of questions and he may just not be an expert at it (most clever people aren't). He is far better off just looking a little wilted and evasive. People who try to be clever tend to end up looking worse.