Modern Day Foo Fighters - UFO Orbs That Follow Planes

Foo Fighters - the term given by WWII pilots to describe the small Orbs that were known to follow and trail their aircraft, read more about them here.
Also just to clear it up for the newbies, the popular music band headed by Dave Grohl based the name of their group the Foo Fighters on this phenomenon.
Foo Fighters are still not a thing of the past as they still occur today, as seen in the below