It's hard to say, generally it doesn't appear to be the case but there's a possibility this information is secret to the public. But take the NSA for example, it has been looked into a lot by government (e.g. congress) itself behind closed doors and it seems to be pretty useless so far.
> The Privacy and Civil Liberties Oversight Board (PCLOB) also issued a report in which it stated, “we have not identified a single instance involving a threat to the United States in which [bulk collection under Section 215 of the Patriot Act] made a concrete difference in the outcome of a counterterrorism investigation.”
> The Privacy and Civil Liberties Oversight Board (PCLOB) also issued a report in which it stated, “we have not identified a single instance involving a threat to the United States in which [bulk collection under Section 215 of the Patriot Act] made a concrete difference in the outcome of a counterterrorism investigation.”
from: https://www.eff.org/deeplinks/2014/06/top-5-claims-defenders...