Trivia question: Limiting per user networking usage

[Ronald F. Guilmette]

Sorry.  I really should go off and RTFM on this, but I'm kind of pressed
for time, so I'll just ask.

I've gotten myself into a minor verbal altercation with another fellow,
over email, and one of the issues that came up was how to prevent one
user from hogging all of the outbound IPv4 port numbers on some single
machine that has only a single assigned IPv4 address.

I gotta believe that FreeBSD must provide a way to do this, i.e. to
prevent one annoying and mischevious user from screwing all of the rest
of the users using that same system... specifically by hogging all of
the outbound TCP -or- UDP port numbers.  But I have no idea what things
would need to be diddled in order to tweek any such relevant per-user
limits.

I'm guessing that it must be one or more very specific sysctl thingies, yes?

Can someone please throw me a bone here?