Add Yahoo as a preferred source to see more of our stories on Google. If the hyper-militarization of Immigration and Customs Enforcement in places like Minneapolis looks like something out of a war zone -- Iraq in the early 2000s, for example -- you may not be far off: The "imperial boomerang" -- a theory increasingly discussed online -- describes how superpowers develop violent systems of control and surveillance in colonial territories, only to later turn those same tactics inward and use them against their own citizens.