blocking web pages based on content

Is there a way with squid to block pages with obnoxious content. Here
I mean a way other than simply collecting the URLs and adding them to
the list. I'd like to get rid of every site that engages in
"mouse-trapping" or whatever the process, of opening up three new
pages everytime a user closes a browser window, is called. Does Squid
Guard or one of the other potential add-ins do it. [If Browsers can be
configured to not allow it that would work to.]

Is there a guide to all the kinds of obnoxious web content out there?

-- 
Josh Kuperman                       josh@saratoga.lib.ny.us
Saratoga Springs Public Library     phone (518) 584-7860 x 211
49 Henry St                         fax   (518) 584-7866
Saratoga Springs, NY 12866