The losses arn't to your 'agency' but to the companies in your country. So the opinion that "we're doing a lot of good but we can't tell you anything about it because terrorism!" outweighing the costs and lost sales to companies in your country seems pretty ridiculous.

You misunderstood me. The losses are to companies of the country, and the gains are again to companies of the country. I am saying that the gains to the companies by the spying must be much more.