But the context here can hardly be instanced in the case of "conversation". Before protecting exchanges (in privacy and anonymity), there is the act of accessing information that would make an intruder an eavesdropping peeping tom.
It is more clear in its actual context: the "private space", which could be breached by so-called "intrusion upon seclusion" cases (peeping, eavesdropping etc.), is protected - see e.g. the case of the "IV amendment" (discussed nearby), protecting against the intrusion in one's «papers» (instance of a broader private space relevant to the explicit context of «searching» as primary practical concern), and base for more specific legislation, possibly after Warren and Brandeis' "The Right to Privacy" - which is relevant because further legislation got needed after new technical-aided phenomena (the gossip press) breaching base principles otherwise formerly threatened by «the idle and... the vicious» (Warren and Brandeis).
So: having rights about a private space, one's act of accessing information must be in anonymous form.