We are seeing the same thing from about 7.5 hours ago (about 21:30UTC on the 27th), along with other strangeness in the entities.
Random example I just picked gives media entities via the rest API for ‘560291409522335746’ but when it came through on the streaming API the media key was missing altogether :
"entities":{
"hashtags":[],
"trends":[],
"urls":[],
"user_mentions":[{"screen_name":"MelissaGeise","name":"Melissa Geise","id":56539140,"id_str":"56539140","indices":[15,28]}],
"symbols":[]
}
Also note that user @libbydink is missing from the above entities, but does appear in the REST API output, and there appears to be new, undocumented entities here ‘trends’, and ‘symbols’.
JB.