No flame here, I think you just nailed down their tactics and strategy for this.
Of course, what happens when the mosques start getting a few letters with white powder ?? That would be an indicator of copycat crimes.
part of the reason I posted a thread about this is I believe that the feds are monitoring message boards sites like this. I am hoping this will at least put into thier thoughts that it is a possibility. I think an email to any agency could easily get lost in the billions they are getting right now.