You know, the more I think about it, the story about drug use is a little too convenient, as well. Brennan could claim that Harris was working for someone else, not him, when he accessed the files, someone who blackmailing over his drug use.
At any rate, Brennan should have been held responsible for the breaching of the passport files.
Oh yes, there are may possibilities to this story. I am convinced that the Chicago thug machine capped Harris, and that they had secure intel to bring it about. Maybe one reason that Obama wanted to have Secret Service protection very early in his campaign, the intel feeds.