Nowadays it is not safely to walk alone, even at a good lighted street. Because there are a lot of bad guys, who wants to rob you. And, how we can prevent this? Of course you could take a license and buy a gun, but, to show it, it takes sometime, in such situations you didn't have this time.

My idea is to create gloves with knifes, which will hides in gloves. Benefits of these gloves are - you can just click, and high sharp blades will extend at few seconds, nobody could see that you have such blades and the last the effect of unexpectedness.