If I didn't have spam filtering turned on for our Wiki, I definitely would not be able to keep it running - here's a bit of the logging, which illustrates the problem:

<< April 13, 2008 10:49:48.216 >>
<< Spam from: (IP Omitted) >>
<< Spam Intended For: Cincom Smalltalk >>

<< April 13, 2008 10:49:48.781 >>
<< Spam from: (IP Omitted) >>
<< Spam Intended For: Wiki Syntax >>

<< April 13, 2008 10:49:59.142 >>
<< Spam from: (IP Omitted) >>
<< Spam Intended For: Add an action button to a canvas >>

<< April 13, 2008 10:51:29.850 >>
<< Spam from: (IP Omitted) >>
<< Spam Intended For: Wiki Syntax >>

<< April 13, 2008 10:54:22.129 >>
<< Spam from: (IP Omitted) >>
<< Spam Intended For: VW NameSpace Reservations >>

It's like that 24x7.