You may ask why and the answer is fairly simple. In this day and age, your PC and the net can provide you with endless data, not only on yourself, but anyone you choose to look for. Try this link and see what I mean:
http://www.whitepages.com/
Put your name in and you will even be able to see your home (aerial view), if the data is available, which it is 80% of the time. Or, just try your telephone number in the reverse white pages, it will give you the same information.
So, what is the purpose of having a P. O. Box. If you leave your mail unattended (from delivery by the post person till the time that you pick it up) in your home mail box for periods of over 10 minutes, or it is not a locked mail box (partially safe although break ins into this type of device have been on the increase), then you should consider a Post Office box. Using a P. O. box for just keeping your address off the net is not the best thing to do; it just gives a sense of false security.
I took all the people that I know who have P. O. boxes and by using that address (the P. O. box), found where the actually lived. What is particularly insidious is that you can get directions to that house and even "case the joint" (aerial view of the surrounding area) to make plans for break ins and get aways!!!!
I am sure that we as collectors employ other means to keep our collections safe (bolted down safes, alarm systems, NRA membership and such), however, I just wanted to make this point concerning P. O. boxes. Yes, they do serve a purpose, but they do not give us the privacy wanted.
BJ Neff