Cloudflare, a host used by a lot of people apparently, made it painfully obvious some people in the industry don't know the difference between a whitelist and a blacklist, and that there are two very specific problems you can solve with them. In fact, I see that modern day programmers are so blissfully unaware of some programming issues (performance, compatibility, that sort of thing) that I end up writing the same message to a lot of people... better share it here as well, maybe it helps
Anyway, let's say you have a bar. Members only. A selected few may enter your club/bar after going through screening, payment processing, health check to make sure there are no STD's, parental checks to make sure their dad's not a judge or something, you name it. Your club, your rules... but there will be a bouncer at the door that has a WHITELIST. You want to know exactly who's inside and nobody else... that's what a whitelist is for.
If you run a less classy bar, let's call it The Hun's Schmutzige Mutze, the bar basically just has to be full. You want a lot of people in there, partytime, long, short, fat, skinny, doesn't matter, as long as they're in! But... there's always a few troublemakers. You don't want to allow the people in that caused a big fight over who's turn it was to toss the midget over the bar or who it was that deliberately punctured your rubbers. Those troublemakers should not come in again. The bouncer at that bar will have a BLACKLIST, if you're not on the list you're presumed innocent and may proceed...
Now... why the fuck am I talking about bars. Well... the same goes for websites... if you have a paysite you only want to allow people that paid you. So you'll use a whitelist. If you build an ad to promote your paysite (in this case: a gallery), you want everybody to be able to see your ads, you don't want that behind a whitelist. Maybe you want to block some people that caused problems in the beginning, that's fine, but you need a blacklist for that...
CloudFlare is an example of using the wrong list at the wrong time, or I should say: some people using CloudFlare as their host... They offer this feature that blocks people with an unknown browser signature from their sites. So if Chrome comes with a new signature it will be blocked, if people have an obscure browser that's not in the list CloudFlare recognizes they will be blocked. You don't know who you're blocking if you use a whitelist. And if you have your stuff listed on thehun you don't know beforehand who will be visiting you. They should ALL get access though. I have to remove sites from The Hun if they have this feature switched on since some people get redirected, lowering the experience on my site...
So, and this goes for galleries on The Hun, but I'm 100% sure the same thing is true on many different settings as well, don't use a WHITELIST if you really mean to your a BLACKLIST... and not only for browser signatures, but also for referrals. Some galleries are set up to allow traffic from thehun.net only, but what if people use a proxy for instance...
Anyway, had to share this, if you don't submit to thehun, fine, learn from it anyway, I'm sure it can help others. I see a lot of things 'modern' programmers now do wrong in sooooo many ways... WorldPress galleries for instance... resources don't seem to matter anymore, optimization doesn't even exist anymore. I'm an old school programmer. And I kept up with modern technology with that old school approach. Which means I'll always go for using the least amount of resources. We were amongst the first to have a responsive site, working on both desktop and mobile devices, we had endless scrolling working before even Facebook figured out how to do that correctly... I'll be sharing more in the future