I love love love these big feathery headdresses - they're so detailed and beautiful, and I'm a sucker for anything that has inherent meaning within the details! It's easy to see how someone would try to appropriate them for style-reasons.

I remember that when I lived in British Columbia, there was so much first nations cultural art from that region that they would frequently be infusing those designs into non-tribe specific things. It was always a topic of conversation up there, and it was always a mixed bag of responses from the Bands. Some of them (usually older generations) thought it was offensive, and some of them liked that their arts and stories were being woven into the province's identity.

I think it's a delicate balance - if you're going to appropriate something, then at least do the research and know what you're saying by using those designs, particularly if you're not of that original culture. Preferably get someone who is experienced in the symbols of that culture and an active part of that culture to weigh in. As you say, these days there's really no excuse for ignorance!!