it cannot be accessed by programs if it is marked as 'not public', even if you provide your login and want to access your scratchpad.

Wanna bet? :) (replace 'xxxxxx' in below code with your homenode id)

use LWP::Simple;
use XML::Simple;

my $home_id = 'xxxxxx';

my $f = XMLin(get
  'http://www.perlmonks.org/index.pl?node_id=' .
  $home_id . '&displaytype=xml'
);

print $f->{data}{field}{scratchpad}{content};
[download]

Update, moments after posting this reply: I am too tired. My eyes read "it cannot be accessed by programs even if it is marked as 'not public'". I still maintain that you can get the scratchpad contents of a non-public scratchpad. Simply parse the textarea from the edit user information page. Also, why do you mention that as a bad side effect of scratchpads? You can't access the personal nodelet in any special outside manner either...