Originally Posted by NW Mourning

The blue light notifies the FA that your seat has been soaked with some noxious liquid and that it should be thoroughly cleaned before anyone is allowed to sit in it. The previous occupant was probably either a toddler whose parents did not wake to take him to the head or, perhaps, a young man like the one who sat by me on a transpac and spilled his 8th glass of wine all over his laptop and mine.

PS: Anyone know a good source for a used macbook?