That would get extremely bulky in mass-adoption, in both local storage
   and network usage. Currently they have some structure to create tiered
   "streams", but that still doesn't eliminate the excessive network
   burden, it just saves some disk space.
   The streams work in a hierarchy, with the uppermost assuming the
   highest network burden. Because it's necessary to send an
   acknowledgement message, a complete circuit must established (though
   not all at once) between nodes.
   Also "broadcast messages" seem too risky to me. They're liable to be
   abused and cause a DoS if this protocol is adopted on a large-scale.
   Proof-of-work doesn't protect broadcast message abuse, because an
   attacker could just use a small botnet to generate a bunch of
   untransmitted messages with similar timestamps for a future date. Once
   that date arrives, then the attacker could just submit a very large
   batch of valid broadcast bitmessages.
   I can't think of a solution to either of these problems right now, but
   I otherwise think Bitmessage is a great idea. It's current, humbly
   sized userbase makes for comfortable testing.
   [1]https://bitmessage.org/bitmessage.pdf
   James
   On 25 October 2013 01:41, Russ Nelson <[2]nelson@crynwr.com> wrote:

     I haven't seen any discussion of BitMessage
     ([3]http://bitmessage.org)
     here yet. The idea is to be a mixer with a pool of recipients, which
     currently seems to be 12,000ish. Before anybody will receive your
     message, they need to see a proof of work. Once they do, they
     forward
     the message to everyone else, using a flood-fill algorithm. Messages
     are encrypted so only the recipient can decode them. Mailing lists
     are
     simulated via a shared private key.
     It looks plausible. Not obviously snake oil.
     --
     --my blog is at [4]http://blog.russnelson.com
     Crynwr supports open source software
     521 Pleasant Valley Rd. | [5]+1 315-600-8815
     Potsdam, NY 13676-3213 | Sheepdog
     _______________________________________________
     The cryptography mailing list
     [6]cryptography@metzdowd.com
     [7]http://www.metzdowd.com/mailman/listinfo/cryptography

References

   1. https://bitmessage.org/bitmessage.pdf
   2. mailto:nelson@crynwr.com
   3. http://bitmessage.org/
   4. http://blog.russnelson.com/
   5. tel:+1 315-600-8815
   6. mailto:cryptography@metzdowd.com
   7. http://www.metzdowd.com/mailman/listinfo/cryptography