limiting \l [list all databases]

Greetings!

I apologize if this has been previously posted..

I run a server with multiple clients running databases on one server,
and I was wondering if there was a way to limit the list all databases
function within the pgsql program to only list databases within a
criteria, say, what they have permission to see?

Or perhaps, if that is not possible, a way to shut off the
functionality entirely, from the server side?

Thanks so much!

Justin