Well, I don't know if this counts, but its def. an interesting sight.
On my cruise last month, my gf was getting changed in our room as we left NYC. She was still very excited about the balcony, and how amazing it was. So, she decided to wave her uncovered butt out the balcony saying "This is so cool! I'm naked outside, and no one can see me!!" Right then, an NYPD helicopter flew by slowly, level with the balcony and about 30 yards from the ship! What timing!
I can't remember if I told this story or not, but it still cracks me up. There is a pic of the helicopter in the Lido deck if anyone wants to see it. But not my gf's butt, sorry