I completely agree that those people with Animal Liberation Front are completely off the deep end. I'm Vegan, and do work with Vegan outreach to try to educate people about animal crultey, and try to do as much as I practicly can to minimize the amount of suffer that I cause, but to actually go out and harm others (human or animal) is just wrong. To claim that doing so is for the greater good is at best shortsighted and misguided and at worst a bad excuse to chanel one's anger into violent actions.
Now, quite a bit of Animal testing is completely uncalled for and excessivly cruel, especially in the cosmetics industry. However, there are many cases in which the advancement of medical and scientific method requires the use of live test subjects. There's just no way of getting around that. I actually work in a lab where there's a fair amount of animal testing done for research into tissue preservation, and even though I'm not directly working on that project, I still sometimes struggle with the ethical delimas that it creates. However, I accept that if we choose to live in a society that depends on the usage of modern medicine, there's no real way around that. We have a duty to be as humane and careful as we can possibly be, but there will always be hard and even awful things that have to happen.
One of the saddest aspects of this whole mess is that fact that these people are erroding the support for a cause that I care about, too. If you want to educate people about anything, threatening or hurting them is pretty much the worst thing you can do.