I agree. While I'm not vegan, I am vegetarian, and I don't use/wear materials made from animals. I know there are people out there who do not harm the sheep they get the wool from, however, just because a person claims they don't harm the sheep doesn't always mean that's true. I think one would have to do a lot of research on an individual/company to be sure no sheep are being harmed.
An example (though not related to sheep) is the Ringling Bros. Circus. Recently I took part in the Denny's boycott because they were supporting the Ringling Bros. Circus. I wrote to Denny's expressing my disappointment and stating I would no longer patronize their restaurant until they stopped supporting the circus. I received an e-mail back from Denny's and they pointed out they had done research on Barnum and Bailey and they were absolutely confident there was no animal abuse taking place within the circus. They even directed me to a website that was filled with all this information about how the Ringling Bros. treats the animals humanely and the animals receive the utmost care. What I found rather humorous is it was Ringling's OWN site! Of course they are going to say they treat the animals humanely and take the utmost care of them! Like they're really going to come right out and say, "yes, we abuse the elephants, come see the show!"
I don't use animal fibers because more times than not, there is going to be some kind of abuse or inhumane treatment towards the animals (trust me, I've done a TON of research, from the time I was 17 to the present, on animal rights issues) that are used for their wool or fur or hides, whatever and, with the selection of non-animal fibers available I do not need to use animal based fibers. Even if a person claims their animals are not hurt in the process, I would rather play it safe and not buy the fiber at all than risk being lied to and have an animal suffer for my vanity.