Read this, or you'll be dead sorry. Why secret services and criminal organisations sometimes make threats with unspecific demands

Criminal organisations and secret services occasionally send bold but ambiguous threats, such as dead fish (mafia) or misplaced chairs at the recipient’s home (Securitate). Why not always tell the recipient precisely what is expected? I show that uncertainty about the level of effort that the recipient is able to provide is one possible explanation. In a game in which a sender can demand specific or unspecific effort and punish the recipient upon observing the provided level of effort, I show that there are equilibria with full compliance from high ability recipients with a specific message demanding high effort, and partial compliance with an unspecific message. But, although costly loss of reputation if a threat is not followed through when an exactly specified demand is not met can make the threat credible and enforce highest possible effort, this cost may simply not be worth it when it cannot be fully eliminated through punishment of non-compliant recipients and some recipients are simply not able to comply. The sender then prefers an unspecific message. If reputation loss is very costly and alleviation through punishment low and the probability of a high ability recipient and relative payoff to the sender from high effort low, even a specific message demanding low effort is preferred. In that case, there is partial compliance in equilibrium only in the subgame in which the sender is unspecific about desired effort.