A computer-implemented method, comprising: examining, by one or more processors, an ongoing message exchange thread between two or more participants operating two or more respective message exchange clients; determining, by one or more of the processors, based at least in part on the examining, a likelihood that one or more messages directed by one of the two or more participants to another of the two or more participants as part of the ongoing message exchange thread would be deemed private by at least a given participant of the two or more participants; determining, by one or more of the processors, that the determined likelihood satisfies one or more thresholds; transitioning a first message exchange client of the two or more message exchange clients into a private state in response to determining that the determined likelihood satisfies one or more thresholds, wherein in the private state, the first message exchange client of the two or more message exchange clients obfuscates at least a portion of a log of messages exchanged as part of the ongoing message exchange thread or refrains at least temporarily from updating the log of messages exchanged as part of the ongoing message exchange thread; transmitting, from the first message exchange client of the two or more message exchange clients to a second message exchange client of the two or more message exchange clients, a command that causes the second message exchange client to transition to the private state, wherein the transmitting is performed in response to determining that the determined likelihood satisfies the one or more thresholds; and transitioning one or more of the two or more message exchange clients out of the private state based at least in part on the examining. examining, by one or more processors, an ongoing message exchange thread between two or more participants operating two or more respective message exchange clients; determining, by one or more of the processors, based at least in part on the examining, a likelihood that one or more messages directed by one of the two or more participants to another of the two or more participants as part of the ongoing message exchange thread would be deemed private by at least a given participant of the two or more participants; determining, by one or more of the processors, that the determined likelihood satisfies one or more thresholds; transitioning a first message exchange client of the two or more message exchange clients into a private state in response to determining that the determined likelihood satisfies one or more thresholds, wherein in the private state, the first message exchange client of the two or more message exchange clients obfuscates at least a portion of a log of messages exchanged as part of the ongoing message exchange thread or refrains at least temporarily from updating the log of messages exchanged as part of the ongoing message exchange thread; transmitting, from the first message exchange client of the two or more message exchange clients to a second message exchange client of the two or more message exchange clients, a command that causes the second message exchange client to transition to the private state, wherein the transmitting is performed in response to determining that the determined likelihood satisfies the one or more thresholds; and transitioning one or more of the two or more message exchange clients out of the private state based at least in part on the examining.