Mother of all selection biases. We only know their failures. Their victories, by definition, are unknown to us.
In what possible scenario could we ever hope to learn the full extent of their crimes? Intelligence agencies burn their records when they are threatened. The Stasi had to destroy paper records, which they failed to do rapidly enough to prevent the public from physically seizing them. The CIA watched this happen. They learned from those mistakes. And this time, only encryption keys need to be shredded to put those documents beyond our reach.
In what possible scenario could we ever hope to learn the full extent of their crimes? Intelligence agencies burn their records when they are threatened. The Stasi had to destroy paper records, which they failed to do rapidly enough to prevent the public from physically seizing them. The CIA watched this happen. They learned from those mistakes. And this time, only encryption keys need to be shredded to put those documents beyond our reach.