Oh, interesting. What's at the intersection of networking and amateur radio that these address blocks are often used for?

Quite a lot of interesting stuff - for example there are mesh networks setup worldwide that attempt to run IP over RF using these - and then use the internet to forward packets from one to another.

They also offer simpler ‘turn-key’ wireguard tunnels too for things like Web SDR setups.

For BGP direct announce in practice it seems to be in the spirt of non-commercial ‘self learning and experimentation’ which is what a lot of legislatures around the world do use as their base definition for the ‘amateur’ in amateur radio. So I guess much like having slices of radio frequencies reserved for it, we’re lucky there are slices of address space reserved for this.