[sudo-users] restricting users

[tony.chamberlain at lemko.com]

They asked me to do something so that if this happens:

  $ sudo ls
  Password:
  Sorry, try again.
  Password:
  Sorry, try again.
  Password:
  Sorry, try again.
  sudo: 3 incorrect password attempts

maybe twice, then the next time it either just locks up or says something
like "too many password attempts.  You are blocked for 2 hours".

Anyway to do this?

On a similar note, using visudo I put

   Defaults insults

which is supposed to insult you when you enter a wrong password, but it is
still saying "  Sorry, try again.".  DO you know why?