I think their point is that the commonality of a military-grade armored vehicle on the roads of civilian America operated by police officers whose job it is to respond to domestic threats responsibly is yet another piece of evidence supporting the theory that the government has militarized against the citizenry.
Which is a sub-issue of whether the United States government is actually militarizing against the citizenry and subverting democratic values.
Which is the debate you guys have not been having in the gun thread, the cliven bundy thread, and now this one lol.