A friend of mine once wisely said that we should not expect revolutionaries to be moderate. I have no time for PETA, its 'ruler-for-life' seems to be one of those people Colin Wilson called 'Right Men' ( or Right Women' this time) who can't abide being questioned or challenged.
Doesn't rule out animal activism as worthwhile and ethical stance.
BTW fish don't count - they are slimey.