Keeping Things Quiet

What happens in Vegas, Stays in Vegas.
Welcome to Compton. No Snitches.

It is entirely reasonable that one might want to suppress information about something. Maybe pass around some hush money or threats, or simply hunt down the relevant information and delete it from archives. This makes things more difficult for people trying to find the information that you are trying to conceal - at least, it does if you do it right. The number of ways one could potentially go about suppressing things is innumerate, and from the standpoint of investigators it often doesn't really matter that much. As soon as you mention Mr. Jones, the bar tender just clams up, and you don't really care whether the head of the criminal organization threatened peoples' families or offered a standing bounty on "not snitching" or whatever.

From a practical standpoint, suppressing information is a threshold 2 check. Net hits increase the threshold to find things out about the suppressed topic. What test is actually made to do that varies based on what is being suppressed and how one is going about doing it. Logic + Bureaucracy might be used to forge civic records, while Willpower + Expression might be used to propagandize people to not talk about something with outsiders. A character can even psyche themselves up to resist an interrogation, generally with a Willpower + Intimidate check.

These sorts of things can backfire spectacularly. If the character fails to get 2 hits, their shortfall is actually applied as a reduction in the threshold of future investigators. If you just yoink the tax records of the people you are trying to make vanish, it actually makes them stick out like a sore thumb because they have obvious shenanigans going on with their tax records.