The short answer: Everyone who wants to.
The long answer: Seriously, everyone who wants to. Everyone considers different things acceptable. If you eat meat, but think wearing fur is wrong, and it bothers you enough for you to want to take action, go for it*. Write a letter. Attend a demo. Do whatever you can to end the suffering you've witnessed.
You may be afraid others will consider you a hypocrite if you advocate for some animal issues and not others, but fuck them. You're not doing it for the dude with the shoes made out of recycled condoms** and the Leaping Bunny tattoo. You're doing it for the animals and they need all the help they can get. If the animals could only depend on vegans to speak for them, they'd be pretty well fucked; there aren't that many of us.
That being said, Martha Stewart's promo for Farm Sanctuary pisses me right the fuck off. Not because she's not vegan, but because she directly profits from animal exploitation and abuse. Whole Foods is one of her sponsors. She's not speaking out against factory farms out of concern for the animals, but because she profits when people buy "happy meat" instead.
Should we be glad more people are converting to cage free/free range/grass fed/raised-in-a-spa animal products? Maybe. Probably not. Organically raised animals may suffer less than factory farmed ones, but there's no doubt that they still suffer. And die. If there are people who are currently eating happy meat who would have gone vegan if they didn't have this "more ethical" option, then more animals are suffering than would have if people like Martha weren't pushing these farming methods. And that's fucked up.
*But maybe also take a moment to sit down and think about why.
**Can we make this happen? Please?