Some of the video should be kept safe from prying eyes

This would be helpful in future versions, perhaps, because this software's next big step could be to allow centralization of video clip storage in a network environment. an iPhoto server and an iDive server would be fantastic additions to any media-rich network!! But without security on the items, people probably would not want to post their work.
Security within iDive could help in Film Lab environments where groups of students may access the same libraries but not need access to all video within those libraries for a certain project.
Merci