Old reddit is much more secure. I have a large banner across my personal bookmarking subreddit. It's so obstructive that it blocks the 'submit post' button. Unless of course you know the secret physical password, resizing the browsing window until a couple pixels at the top are above the banner. If I put that on every subreddit I mod, it'd be a captcha for low-effort posters. It deters me from posting in the subreddit only I can post in.