Based on what you see on the internet you could come to the conclusion that Japan has more than its share of perverts.  In an effort to ward off modified camera phones with IR night vision capability that can see through clothes the Shotguard Inner Shorts were created so that you can wear underwaer that will block the IR.   There is enough in this world to worry about without having to protect ones privates from people with modified x-ray vision cameras.   

http://gizmodo.com/gadgets/japan/japanese-anti+pervert-panties-block-ir-284523.php