This morning I got up in the bitter cold to walk our new puppy. I did not want to do it, but if he does not get his exercise in he turns into a total spaz by the end of the day (instead of just a partial spaz). When we were done walking I opened up my garage door to get back into the house using the keypad. Because it was so cold I was not patient enough for the door to go up completely before I went inside. Because it was so cold I had my hood pulled up so that my peripheral vision was completely...
If you read enough about security in general you will hear the often touted principle of do not rely on security by obscurity. It even has its own Wikipedia page. You see this advice thrown out a lot when somebody does something like embedding encryption keys in their code. The developers assumption is that the code will never be read by anyone and thus the key is safe. I have personally seen that one cracked in about one minute. So the advice is good, you should not RELY on security by obscurity....