I have connected to the stream for over a month now for an app I have been developing. One of the key components of my app is to use the coordinates key data where I only use tweets where this field IS NOT null. Up until April 27th, well over 90% of tweets had coordinates availalble. Then over a 6 hour period starting 18:00GMT on April 27th, the amount of nulls increase drastically. Now ~80% of the twets have this field marked as null which means I am only using 20% compared to the >90% before. It is 36 hours later and things still have not gotten back to where they were before.
Was there a change made to streaming tweets filtered on location? I have not found anything on this site or other popular forums.