Ham would be incredibly hard to jam the entire grid since there's a huge amount of regular channels and plenty of gray area, the entire ham grid is independent of any gov input other than the FCC policing them occasional. They could potentially jam a couple of hundred areas but short of JBT knocking doors it would be impossible to take the HAM out of the equation. HAM guys know their electronics better than most engineers. There's a thread on getoffthex about it and they're saying that it's been done to bounce a signal off the moon or meteors using sharks with friggin lasers on their heads or some such technical stuff.

It's on my list of future hobbies.