[messaging] Group messaging consistency under resource constraints

[David Leon Gil]

On Thu, Oct 16, 2014 at 1:37 PM, Trevor Perrin <trevp at trevp.net> wrote:
> Pond doesn't have a notion of group messages.  But if it did, I
> imagine they would still have these properties (in particular, I
> imagine users would *not* want to reveal to mailbox servers what
> groups they are members of, since hiding relationships is the point of
> Pond).  So if the sender goes offline, there's no-one else who can
> re-transmit a lost message.

As a note re Pond: It doesn't do a good job concealing social-network
information. In particular, the single-identity-per-client constraint
means that any two colluding participants can determine that they're
talking to the same person.