I think they should be more worried about the militarization of the police in the US.
I agree completely. When I was working at the Cato Institute, one of the scholars there, Radley Balko, specialized in this matter. It's troublesome in a lot of ways, many of which might not occur to some people.
For example, with the rise in the use of military-style "no knock" raids, where SWAT teams storm a house with flash-bang grenades and the like, there has been a corresponding increase in the number of homes being wrongly invaded due to the SWAT team having the wrong address. This, in turn, has resulted in an increase in the number of homeowners naturally assuming that their homes are under attack by criminals and responding with gunfire. In such cases, if the homeowner is killed, the police are typically pardoned, whereas if the homeowner kills any of the police officers (and lives to tell the tale), he is typically convicted of homicide.
I highly recommend Radley's white paper on the subject:http://www.cato.org/sites/cato.org/files/pubs/pdf/balko_whitepaper_2006.pdf
It's a very long read, but it's absolutely worth it.