@jankusanagi@datamost.com I see that you didn't read that "long story" I referred to in my previous note ;-)
The point is _not_ about client applications.
There could be lots of reasons, why a client application sends duplicated posts: incorrect implementation (like the yesterday's test post), communication problem (e.g. when that HTTP 200 response from a server was not delivered back to a client) or even deliberate decision of a User to send the same post again and again... - In any case a server should not unintelligently deliver the same content to the same audience...
If you're interested in this topic, please start from reading https://github.com/andstatus/andstatus/issues/83
As a side note: I see that a reply to a note with a title should by default have the same title. Like for emails?!