I don't think the government has the duty of disclosing that information to the public (or even the suspect) until it charges him. It'd be pretty silly if they did.
They need to convince someone, say a judge, to issue the subpoena/warrant.
They need to convince someone, say a judge, to issue the subpoena/warrant.
They may not have the duty to disclose, however, the warrant/subpoena has to be specific, and what IS scary is the idea that those served can be put under a gag order not to talk about it. For big RICO cases it made sense, but for smaller ones that's an abuse.