I use tiger as a reporter of potential problems.
Usually I get this message:

# Checking listening processes
NEW: --WARN-- [lin003w] The process `smtpd' is listening on socket 25 (TCP on every interface) is run by postfix.

Fair. I do use postfix for my email.

I occasionally get another message about a port that Chrome or
Chromium opens to announce my printer to the entire world.
Tiger is being fair, but chrome/chromium is not.

But what puzzles me is that I also have a webserver running
that's accessible to the world, and its use of a port never
shows up on these reports. Any ideas why not?

-- hendrik