Depends on what you mean by extremist. These days extremist seems to be synonymous with terrorism and violence, in which case that is more an ALF thing (and possibly the others too due to various allegations of connections with ALF, etc.). If going with the more classic sense of just holding extreme views, using radical methods and fanaticism issues, then organisations like PETA and possibly HSUS can come under the name. There are quite a few people who find the publicity activities, especially of PETA, to be misleading or sometimes outright counter-productive, while overshadowing more mundane animal protection activities.
While I wouldn't equate HSUS and PETA, HSUS does have some issues that may lead people to categorize both together as unhelpful. I think the largest issue is that way too many people think by giving to HSUS they are helping local animal shelters, that it is some sort of hierarchical organization. And there have been complaints of more directly misleading advertising campaigns in regards to what the money is actually being used for.
Depends on what you mean by extremist. These days extremist seems to be synonymous with terrorism and violence, in which case that is more an ALF thing (and possibly the others too due to various allegations of connections with ALF, etc.). If going with the more classic sense of just holding extreme views, using radical methods and fanaticism issues, then organisations like PETA and possibly HSUS can come under the name. There are quite a few people who find the publicity activities, especially of PETA, to be misleading or sometimes outright counter-productive, while overshadowing more mundane animal protection activities.
While I wouldn't equate HSUS and PETA, HSUS does have some issues that may lead people to categorize both together as unhelpful. I think the largest issue is that way too many people think by giving to HSUS they are helping local animal shelters, that it is some sort of hierarchical organization. And there have been complaints of more directly misleading advertising campaigns in regards to what the money is actually being used for.