Red Ensign - in my old job, I rescued an old ship's compass binnacle stand (wooden stand with brass compass on top) that was returned to supply for disposal by a local Sea Cadet Corps. Based on condition and age, it appears to be WW2 era, but not in such condition that it was interesting to the Naval Museum in Halifax (I had the curator come down and look at it.)
So, it was instead positioned in the entry space to my office area.
I also recovered a pair of old Chaff Rocket test/dummies that I put on display to each side of it (bronze, marked INERT) and found a couple of flag poles. I put up a Canadian Flag, and, to suit the age of the Binnacle, I added a Red Ensign - as would have been the correct flag to have been flown by the ship that the Binnacle originally came from.
It's probably the only Red Ensign still on 'display' on the base outside of the Naval Museum, but, in the historical context of the Binnacle, it is suitable, and my Chain of Command agreed. It's still on display today, over 5 years later in that office.
That said, context is everything. If the Binnacle wasn't there, (and the Anchor I found too...another story...) then there would NOT be a good reason for that flag to be posted - and it would not have been posted.
So.
Why are people flying the flag of palestine?
Is it because they wish to raise awareness of the circumstance and are concerned about the problems going on over there? Have they been out in their front yard cheering 'river to the sea'? Were they out celebrating on the 7/8 October, cheering and setting off fireworks?
Motive matters.
Context matters.