Right now the web UI exposes every piece of metadata in a tweet to end-users. That is, an end-user can use twitter.com to check the complete contents of tweet sent by an application. I didn't see anything in the proposals regarding the annotation feature that says that users will be able to see all the annotations through the web UI. And, even if they could see them, chances are they couldn't understand them. And, even if end-users could understand them, applications will be able to use encryption and other obfuscation to make them impossible to interpret. This reduces the amount of control users have over their tweets.
Right now an application cannot disclose the user's location in a tweet, except by putting the location information in the tweet text (which the user can see very clearly), or by putting the location information in the built-in geo feature. The ability for applications to expose the user's information is controlled by a preference that can be controlled only by the official web interface on twitter.com. However, with the annotations feature, applications will be able to expose the user's location-again, possibly encrypted or otherwise obfuscated-even when application access to the location feature is disabled. It doesn't make sense to disable an applications' access to the geo feature and then let it silently and undetectably disclose the user's location-perhaps in even more detail than the built-in geo feature allows. I think there must be some kind of control mechanism in place for annotations, or the web UI must present all the annotations of a user's tweets to that user, or both, in order to prevent the annotations feature from becoming a side channel for applications to communicate users' private information without users' knowledge or consent. I would like to know more about how this is going to be done. Thanks, Brian -- Subscription settings: http://groups.google.com/group/twitter-development-talk/subscribe?hl=en