Security, is an issue thats always been a number one priority. Even our free
vB mp3 player's PHP controlled XML read cannot be accessed via any browser. Many people have already asked why they can't see information from it's index file, this also gives a white page and can only be accessed via the flash file.
Part of the system, will not be using PHP - since we have coders that can code in Perl with better security, when uploading files. All modifications are checked prior to release, by top coders - if any leaks are found they are fixed immediately.
The system will be fully integrated into vBulletin's user permission system, no files will be accessible via just browsing any files - since we don't use standard programming methods. So you can rest assured security on this project will be high and not an issue.