Surely this has nothing to do with the “religion of peace”. Inch’allah, piss be upon him.
Not much. It's common in some Muslim countries, but then in most of those countries minority religious groups such as Druze and Christians also practice it.
Meanwhile, there are many Muslim countries where the practice is unknown.
Personally I prefer the old Spanish method of cleansing the family's honor: track down and kill the rapist or seducer.