I just want to stop the casual downloaders, and the people who may have been ticked off because they were refused permission to join (they were found guilty in court of violating copyright violations).
File structure is public_html/area51/files. "area51" has Options -Indexes in its .htaccess file. Maybe "files" should too, I'll play with that. At least this way, they have to know the exact name of a file before downloading, it doesn't appear they can just start at index.html and download everything by reference.
The "files to download" page is a post in a private forum in Invision Power Board, so the filenames are hopefully available only to subscribers.