some do it for looks, but it really is to hold the hood down. once you hear a horror story of someones c/f hood flying up at high speeds and slamming the windshield, you will see their use. for security, i have seen locking hood pins. but what you need to do is protect them from popping the hood in the first place. your hood cable(how you pop it up from inside the car) is easy to get to from outside the car. you can relocate it, or make a plate or something to protect it, or just boobie-trap it by placing razor blades in your fender under the cable so the next time someone tries to pop the hood, their hand will pay. or you can do any combo of the above to protect it.
