> If both Petraeus and Broadwell had used GMail accounts not associated with their names, such Dave501010@gmail.com and PaulSmith900@gmail.com, how likely is it that anyone would discover their shenanigans?

I'd argue that every security agency worth its salt is also keeping a close watch on its bosses (especially on its bosses) so that let's say if Petraeus had logged in with joe.doe@gmail.com his communications being intercepted someone would have noticed. As a non-American, I'm not exactly sure what's for example the relation between the NSA and CIA, but I guess it's somehow telling that the whole thing seems to have been driven by the FBI