Re: [PATCH v2] net: introduce ip_local_unbindable_ports sysctl

It's a form of one, agreed, although let's be honest - someone reading
the transparent proxy use case in the commit message will not think of
a complex AP scenario, but rather of a locally configured transparent
proxy with IPtables or sockets or such.

Transparent proxy could be implemented using eBPF + XDP and those don't
need sockets. However, in that case we do need to block those specific 
ports
to avoid messing with unrelated traffic.