I am pretty sure that any world that is not in a permanent state of fear and tyranny would oppose such mental invasion lest the populace live in fear of thought police and the most minor of slights landing them punishment. Because that is what you are justifying.
And this world Ana has might not be perfect, but it is not that. Not when there are heroes who can oppose such harsh methods while still getting results.
Even the worst of criminals still have basic human rights, and condoning an eye for an eye does not make you any better than them, though you can claim to be on the side of justice. To deny someone, anyone, a right to an unmolested brain is nigh unthinkable. If they consent to it then sure, search, but a mind is not like a static house that can be searched. It is everything that person is and has been.
As I said, if such a search could be tailored to specifically target only the desired memories and completely block any others, then my objections would be much lessened, but free range mental access is just...criminal.
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There is no shame in not knowing; the shame lies in not finding out