The feds conduct a rather massive raid on a company but don't bother to explain why.
Other than "because we can" what explanation is there for that behavior? If the company is illegally selling paperclips to Botswana the raid has already tipped the executives off and they're gonna take that long awaited trip to whatever country doesn't extradite. As well, the Botswanian agents now know you're on to them and are heading back to the mother country for that long needed visit with gramama. Keeping the affidavit under seal only serves to hide information from everybody else.