Before today, the value of the in_reply_to_status_id field was validated by two requirements,:
1) It was set to a valid status_id 2) The valid status_id's author from #1 was @replied in the update (@reply here is the old definition where "@user" was at the beginning of the tweet). If the value of in_reply_to_status_id did not meet these criteria, it was silently dropped. We have relaxed requirement #2 to permit mentions, meaning that the user of the referenced tweet needs to be included somewhere in the update. Enjoy the new data! Thanks, Doug -- Doug Williams Twitter Platform Support http://twitter.com/dougw
