Actually the design of the fence is wrong, every gap should be big enough for a camera lens. If they don't want people in some areas they need a solid wall or dense vegetation.

A few decades ago someone decided chain link fences should be at a 2" hole size which worked well for keeping tennis and other balls going astray. In other applications they just use the standard stuff. Nobody had cameras in 1941 or whenever it was this fencing became popular, so 2" holes have persisted, QWERTY style.

You would need a different machine for making a 10cm hole size but it would be cheaper.

Perhaps they chose a hole size that's hard to fit a shoe into, to make climbing over difficult?

Of course, dense vegetation would be even better, as you say.

True, that is probably the reason why 2" is the hole size. It has been a while since I have bypassed a fence and it would be negligent to have something that worked as good as a ladder!

Normally you find an area that can be lifted up and you can expect barbed wire at the top, climbing is out the question though.

I would go for the bigger holes if it was my fence just so people don't vandalise it by lifting it or cutting the wire.

What gave you the idea that other places would not be allowed anymore? How would safety be impaired by photographers outside fences?

> What gave you the idea that other places would not be allowed anymore?

Well, that's similar to crowd control. They can't block other areas. But there will be less traffic and different monitoring and control requirements for those areas.

> How would safety be impaired by photographers outside fences?

You could use photography as a good cover to do other stuff. For instance, controlling an amateur drone or collecting intel for airport robbery.

I assume it would make sense to monitor activities around the airport fences.