Is it legal to take off with an iced windscreen?
When operating under Part 91, taking off with an iced windshield is not permitted. It does not differentiate between IFR and VFR operations.


  § 91.527 Operating in icing conditions.
  
  (a) No pilot may take off an airplane that has frost, ice, or snow
  adhering to any propeller, windshield, stabilizing or control surface;
  to a powerplant installation; or to an airspeed, altimeter, rate of
  climb, or flight attitude instrument system or wing, except that
  takeoffs may be made with frost under the wing in the area of the fuel
  tanks if authorized by the FAA.


Now in the case that the winshield is simply covered in condensation (not ice), I'm not so sure about that, though it'd be pretty stupid to takeoff without heating the windshield and pretty much zero visibility for no particular reason. In that particular video though, that's definitely ice.