How about impersonating a US military veteran?
I'm not up to the minute on this, but my understanding is this is something that came out of the Vietnam war, but really took off around 2003~04 when people who had never served started taking an interest in being more hawkish and many went all the way by impersonating a military veteran. It was apparently so pervasive by 2010~11 legislation was passed in 2013 criminalizing the practice. There were/are politicians and fortune 500 execs caught taking advantage of the increasing positive public interest in the military. In certain circles, veterans move to the front of the queue quickly when it comes to job offers and promotions. Companies want to appear patriotic by hiring veterans so there is plenty of temptation to impersonate one. People go so far as to do extensive research and memorize amazing amounts of info in order to pass as a combat veteran. From what I understand, even with the prohibition against it, it is still widespread enough a cottage industry of sorts exists to locate and drop a dime on these guys.
Not sure if this is what you had in mind, but it is one of the most widespread acts of impersonation in modern times.
Stolen Valor