And then there's this, from 19 min ago on reddit:
http://www.reddit.com/r/CBTS_Stream/comments/7na57ns/no_call_sign_and_blocked_aircraft_circa_denver/ I had to type in the link and contents by hand, it wouldn't copy or paste.
I've been watching "blocked" (no light details) aircraft on flightradar24 for the last few hours. A blocked aircraft from Fort Lauderdale just landed at Denver half an hour ago, and another blocked aircraft, from Lake Havasu Airpot, Arizona, is flying over Colorado now. There have been several "no call sign" aircraft flying near Denver.
https://www.flightradar24.com/multiview/ffea5ab,ffea2b7,ffea14f,ffea414,ffe855e,ffe6cb4
Having spent so many years in Los Angeles, I’m quite used to these types of escorts for a fallen officer (or fireman) from the scene or hospital to the county morgue. People on the same shift will generally be most of the motorcade with additional units to actually handle traffic and escort duties while they mourn. It was not a spontaneous thing, and is extremely common (especially for graduates from LAPD’s academy which represents about 18% of all law enforcement in the US.)