In the United Kingdom the interventionists are often [citation needed](but not always) members of the Hunt
Saboteurs Association, while the non-interventionists are often members of the League Against Cruel Sports or, more recently, Protect Our Wild Animals or the International Fund for Animal Welfare.
Wikipedia documents the Hunt
Saboteurs Association, supposedly worldwide but does not appear to be active outside the UK, Ireland, and the United States, if they're active even there.