Used as an explanation as to why you are requesting something when you don't want the people to know why. The more sinister your statement sounds in context, the better.

Mercury retrograde is the act of taking a shit whilst mooning one or more human beings. Your day can typically being going well, according to your horoscope, until you are forced into witnessing Mercury retrograde. Performing Mercury retrograde will often speed the astrological cycle forward for the individual performing the Mercury retrograde, bringing about happy and fruitful times to come.

Originally found in an engrish advertisement for Japanese sake, "for reasons" has come into common usage to ironically or sarcastically point out either obvious reasons for a thing, or a complete lack of explanation. It is also used to point out a nonsensical or untrue explanation, or to avoid giving an actual explanation.