saint peter's sky

if you click on this photo you can see the front steps of saint peter's basilica are closed off to the public. you can only enter or exit through the front doors if you walk up the stairs on either side. when I visited years ago the public was able to walk right up the middle of the front steps. though it may seem a small change, it creates a different atmosphere where I find the feeling of the square much less open. I am thinking it must be a security measure.