A tiny plugin that only inserts a hidden input field named keepempty. Bots usually won't keep it empty, and thus we can block any such spam attempts immediately. Real users will want refrain from filling in the hidden input field named keepempty. Should be easy. As should this plugin be. Assuming it is bug free, that is. Please check for yourself, the code is tiny.
Currently blocks stupid bots from submitting new tickets, editing the wiki.
In more detail, you can see the plugin is working if your wiki and ticket forms contain the following:
<div><input type="hidden" name="keepempty" value="" /></div>
As well as that you probably stopped getting comment spam right after installing the input field trap. Note, this spam prevention is meant to stop collateral spamming from bots that spam anything that has a postable <form>.
If you have any issues, create a new ticket.
Download the zipped source from here.
Non-logged in users who fill anything in the robot trap hidden input field get blocked. Applies to wiki pages and ticket submission.