FBI Says It Can't Release iPhone Hacking Tool Because It Might Still Be Useful (zdnet.com)
Justice Dept. officials say that details of a hacking tool used to access a terrorist's iPhone should not be released because it may still be "useful" to federal investigators. From a report: The government is fighting a case against three news organizations, including the Associated Press, which are fighting to release details of the hacking tool that FBI agents used to unlock a passcode-protected phone used by San Bernardino shooter Syed Farook. Details of the hacking tool have remained classified, not least because the Justice Dept. believes the tool may could still be used by the FBI in similar cases. "Disclosure of this information could reasonably be expected to cause serious damage to national security as it would allow hostile entities to discover the current intelligence gathering methods used, as well as the capabilities and limitations of these methods," said David Hardy, section chief of the FBI's records management division, in a court filing released late Monday.
Support President Trump's efforts to fire as many as possible.
If they reveal the tool, and it is revealed it is faulty/suspect in anyway, then the information they "recovered" from the phone(s) all become untrustworthy. That does not support the verse the authorities are trying to play out to the general public. So instead of being proactive and helpful, we get innuendo, and "trust me" type comments, with no hope of verification/validation by the public.
That's what Parallel Construction is for...
The FBI, et al. would rather exist in a world that is very dangerous and they alone possess the tools to (sometimes, maybe) protect us, than live in a world that is a little safer and no one has those tools. This is in the interests of the FBI and not necessarily in the interests of the society it is tasked to protect.