I'm not defending them. But they have revised their practices recently. If you're going to be into activism, you owe it to yourself to be up to date.
I haven't been into any activism in the last 6 months or so until recently but i've only been participating in Earth First! Protests and such, not so much corporate shit. After the Florida Protest against all major food chains a couple months ago i think i heard that Burger King was the only fast food restaurant that agreed to raise the price they were paying for vegetables. And even so, it wasn't by much as I remember. So I'm guessing that you're saying Taco Bell jumped on the bandwagon with them.
Yum! brands is pretty much the devil. But it been more than six months since it's revision.