phpLD has some very powerful methods for dealing with spam, and gives the admin a number of tools for stopping spam. Ban Control is one way (there are others already built into phpLD) the directory admin can help stop spam, including:
Whenever any of these are used in any submission, it stops the submission from getting through. Most of the Ban Control is only needed in extreme cases, because most robotic-type spam submissions are blocked in other ways.
Screenshot:
