I'm surprised no one is talking about the fact that this is a pretty clear shot across twitter's bow. Users are trained to tag friends in instagram shots using

I'm surprised no one is talking about the fact that this is a pretty clear shot across twitter's bow. Users are trained to tag friends in instagram shots using twitter handles, and to generate hashtags for locations and events. This encourages users to move away from that dynamic - effectively removing a large transmission mechanism for instagram via tweeting. Yes, you'll still tweet the pic (maybe), but those in the pic won't be notified. Very clever move to hurt a competitor while boosting internal engagement.