If it's worth saying, but not worth its own post (even in Discussion), then it goes here.
Notes for future OT posters:
1. Please add the 'open_thread' tag.
2. Check if there is an active Open Thread before posting a new one. (Immediately before; refresh the list-of-threads page before posting.)
3. Open Threads should be posted in Discussion, and not Main.
4. Open Threads should start on Monday, and end on Sunday.
I think it depends on where you are; for example, ISTM that supporting animal testing, GMOs, and the like used to be pretty much taboo on Facebook in my country until a few years ago, and I would have felt very uncomfortable expressing ideas that could be construed no matter how broadly as speciesist on my Facebook wall, whereas today there is a sizeable metacontrarian current which is mostly tolerated except by extreme environmentalist wingnuts.
Interesting - where do you live?