I think you're incorrect about the perceived power of a former US president, but regardless I don't think perceived power has any impact on whether the FBI choo

I think you're incorrect about the perceived power of a former US president, but regardless I don't think perceived power has any impact on whether the FBI chooses to investigate or not. That might be a fairy tale some black hats tell themselves, but it seems clear to me that compromising a former president's accounts has serious security implications for the US govt. Obama's access to information (both past and present) is such an overriding concern that his level of perceived power is basically an after-thought. The FBI often helps out with major breaches of all varieties, let alone ones that involve former heads of state. It's extremely unlikely they're not already involved in this one.