For me, being legally compliant and having the permit is like a form of insurance. I hope to never make a claim, but it gives me peace of mind knowing that should the toy be detected that I have a means of legally claiming ownership. When I brought MP36 through airport customs after coming back from Japan, I had my permit in the luggage with the toy so that should Customs officers see it and question me, I can easily show them my permit. I also took photos of my storage case and the door to my TF room with close up shots of the case's padlock and the door's keylock - again, so that I would be able to show it Customs officers. Hope for the best (non-detection) but prepare for the worst (detection).