The Animal Liberation Movement (ALM) consists of small autonomous groups of people all over the world who carry out direct action according to certain guidelines (click here). The ALM evolved from the Animal Liberation Front (ALF), which in turn grew out of the hunt saboteur movement in England in the 1970s.
A short note on effectiveness of A.L. from the website of A.L.F.
"Perhaps the easiest method of accomplishing the mission is to help the world's masses emotionally connect the animals they abuse for food, clothing, and product safety to the domestic companions they love. Many of today's animal rights activists have made this connection after seeing AR protests, reading about direct actions, and almost every other way that our message has been delivered. Sometimes their epiphany comes months after ignoring the AR rhetoric or noise while they are quietly watching a pigeon in the street.
Please plant the seed of thought in someone else's brain that animals have feelings."
And here is a part of A.L.F's Credo, also copied from their website:
The Animal Liberation Front (ALF) carries out direct action against animal abuse in the form of rescuing animals and causing financial loss to animal exploiters, usually through the damage and destruction of property.
The ALF's short-term aim is to save as many animals as possible and directly disrupt the practice of animal abuse. Their long term aim is to end all animal suffering by forcing animal abuse companies out of business.
It is a nonviolent campaign, activists taking all precautions not to harm any animal (human or otherwise).
Because ALF actions may be against the law, activists work anonymously, either in small groups or individually, and do not have any centralized organization or coordination.
The Animal Liberation Front consists of small autonomous groups of people all over the world who carry out direct action according to the ALF guidelines. Any group of people who are vegetarians or vegans and who carry out actions according to ALF guidelines have the right to regard themselves as part of the ALF.
More about A.L.F and A.L.M. read it here. Since Hunt Saboteurs is a part of A.L.M. I am not mentioning them separately as they are an integral part of each other.
You go A.L.F! My eternal support and solidarity!