There seems to be an error with the JSON feed when it comes to retweets. User Alice favourites a tweet from Bob, and then retweets to to Charlie.
The JSON feed that Charlie gets marks Bob's tweet as one of Charlies favourites. This does not happen in the XML feed. JSON (snipped) "created_at" : "Thu Mar 24 15:36:16 +0000 2011", "favorited" : true, "id" : 50944022319087616, "id_str" : "50944022319087616", "retweet_count" : 1, "retweeted" : false, "retweeted_status" : { "contributors" : null, "created_at" : "Thu Mar 24 15:30:23 +0000 2011", "favorited" : true, "id" : 50942542786723840, XML (snipped) <id>50944022319087616</id> <favorited>false</favorited> <retweet_count>1</retweet_count> <retweeted>false</retweeted> <retweeted_status> <id>50942542786723840</id> <favorited>false</favorited> -- Twitter developer documentation and resources: http://dev.twitter.com/doc API updates via Twitter: http://twitter.com/twitterapi Issues/Enhancements Tracker: http://code.google.com/p/twitter-api/issues/list Change your membership to this group: http://groups.google.com/group/twitter-development-talk