I agree a photo could really help. Even with photos it's hard to see everything but a good shot of the carabiner and lock system would really help. And enough to give us an idea of your coop/run. There is no telling what someone might see.
How big are the openings in they fencing material? Can a raccoon stick its hand through or a chicken stick its head out? Where do they roost? Next to the fence where something could grab them through the fence or inside a solid coop well away from the fence?
What do you have at the bottom to stop digging predators? If the ground is not level it doesn't take much of an opening for many different predators to squeeze through, not just raccoons. Raccoons and many others are mostly fur so they can get through very small openings.
How secure are your connections where you connect the wire to the coop or posts? The best materials in the world won't help if all the predator has to do is pull and it comes loose. Your materials, construction techniques,and workmanship all come into play.
Its' hard to say just how secure a lock is from a raccoon. They are intelligent, strong, and really good with their paws and teeth. I've used a carabiner/hasp system for years without a problem and I've trapped a lot of raccoons from that area. It's worked so far. But I don't know how well it has actually been tested. I don't know if a raccoon has actually set down and tried to work the lock. That's one of the problems with predator protection. If it is tested and it fails you generally know. If it is tested and actually worked you usually don't know. There is always the chance that the next one might be a bit luckier or a bit more clever.
The type of carabiner can make a difference too. Is it spring loaded or does it screw shut to lock it? If you are really concerned about it a padlock is about as safe as you can get but my carabiners are a lot more convenient as often as I go into the coop/run in a day.
