In time of war, you often find plenty of irreligious IDF soldiers who want to wear olive drab tzitzit, which they sometimes refer to as their 'bullet-proof vest' because they want to fulfill mitzvah of tzitzit to help protect them from harm.

But it seems that a band of criminals in Netanya took this more literally: they sewed a real bullet-proof vest inside a tzitzit garment.

My big problem with this is that it renders the tzitzit not kosher. If they used the type of vest that's closed on the sides, since they combined the two items to create a single garment, that new garment is no longer considered a four-cornered garment. It's "not a crime" to wear it, but you certainly cannot say a bracha on it, and you wouldn't be fulfilling the mitzvah of tzitzit, i.e. the strings would become essentially a decoration.