Remove search results' excerpts. OR Permission flaw in search.

[photoadmin]

I tried to search for a thread about this here, but couldn't find anything. 

When a guest or any other member uses my regular search feature, the results they get show them an overly generous excerpt of each post on the results list, even if those posts are from forums the searcher does not have permission to access.  This is not good, because upper permissions are being violated by the searcher being able to read up to 3 lines of text in those excerpts.  How can I make it so that only the titles (without excerpt) will show for results?  Or, how can I make it so that posts from a subforum one does not have permission to view don't show on the search results at all?

Thanks for any clue,

--E.