If an Indian wears a fedora, are they insulting my Anglo heritage? Are they ethically wrong?
The answer is 'no'. Indeed, the Indian wearing a fedora could be interpreted as having his culture attacked and diminished by the dominant 'anglo' culture.
To get to the real issue, it's this: as a child I played 'Cowboy and Indian', I watched 'westerns', read 'western' comics. The depiction of Indians in those media may have been prejudiced, but I was born into a culture that includes popular ideas of what Indians are.
I understand the righteousness in education and demanding respect for your people(s). But can you understand the appropriation has already happened and exists now as the American cultural commons artists have a right to?
Which is not to say I want to wear a headdress myself. But I see nothing wrong with a 'hipster' wearing a headdress inspired by Indian headdresses but clearly not the real thing. Had Native Americans had their treaties respected and today held economic and military power to rival the United States--do you suppose you might agree?
Headdresses: Made of revered feathers and specific to Plains Indians. Fedoras: Not made of anything revered and generic to all Westerners. The two aren't comparable.
A lot of hipster headdresses clearly are the real thing. Or close enough to be indistinguishable to the average layperson. For instance, Kesha's. What do you have to say about those, Mike?
As for phony headdresses that resemble children's playthings, they don't have the problem of abusing actual feathers. But they do have the related problem of mocking or trivializing an Indian practice. They create the impression that a chief is anybody who wears a colorful headpiece.
An analogy may help. Headdress-wearing hipsters who carouse and get drunk are like mitre-wearing hipsters who pretend to abuse altar boys. Legally they could do it, but Catholics would be right to feel offended. The hipsters would be mocking or trivializing something Catholics revere.
The point you haven't touched is that wearing a fedora doesn't contribute to a centuries-old pattern of harmful racial stereotyping. Wearing a headdress does. That alone makes it wrong.
A comparable act would be hipsters dressing consistently as conquistadors until people believed all whites were greedy plunderers. Or dressing consistently as Klansmen until people believed all whites were violent racists. Needless to say, that hasn't happened. Society would rightly condemn anything like that as a false and malicious stereotype.
For more on the subject, see The Big Chief and Indian Wannabes.
Below: Two offensive practices that are wrong for the same reasons.