diff --git a/README.org b/README.org
index 832301c..412469a 100644
--- a/README.org
+++ b/README.org
@@ -119,6 +119,9 @@ so the receiving server can decide whom to send the message to.
 Unfortunately this decision breaks the actor model and also our suggested
 solution to authorization; see [[https://github.com/WebOfTrustInfo/rwot9-prague/blob/master/topics-and-advance-readings/ap-unwanted-messages.md#org7937fed][MultiBox]] for a suggestion on how we
 can solve this.
+This is more serious than it seems; we cannot proceed to make the system
+much safer to use without throwing out =sharedInbox= since we will
+lose our ability to make intentional, directed messages.
 
 # - What to do about the holes in the spec?  Many community members have
 #   asked that we codify current behavior.  However, as this document lays