Ok as this discussion has moved on a bit to include different types of media I'll throw something new into the ring.
Archive footage originally widely broadcast on national (possibly international) TV News with clearly identifiable characters/faces shown. Permission from the copyright owner (shooter) has been given to use the footage. If you wanted to use that footage for any subsequent work then do you need model releases? The images are already in the public domain and to this day they can still be accessed and seen online.
Discuss.... 
Cheers, Simon
