It depends on how credible the threat.
It depends on how important the issue was that I was second guessing myself on.
It strikes me that you are the one being emotional here. By using a “always stand up to terror no matter what” approach you are completely ignoring rationality. In the case of Sarkeesian’s talk at USU being cancelled - she is cancelling an event where she was going to talk to some people about feminism. How important is that? There are people out there who place far more importance on her not talking than she places on talking. Basically she’s saying that even if there is a remote possibility that this threat is legit, like say one-in-a-million then 1/1000000 times 15 dead people (Montreal Massacre level violence) is a greater cost than the benefit of her talk.
If your point is that when you make personal decisions about your own life you always have to factor in some long term cost-benefit to society where we let terrorists win or not, I don’t think individuals have to shoulder that burden in their individual decisions. We hire specialists to investigate and prevent these kinds of actions just like we hire specialists to do everything else. Plus, using the same calculation, does one one-millionth of a Montreal Massacre do more to make people in the future afraid than Sarkeesian showing up for her talk and there being no massacre do to make them brave? Considering Sarkeesian has been giving talks for years and I’ve hardly hear of them, I’d say no.
You would never argue that no one should ever do anything to make themselves or other safer because that would be stupid. But it sounds like you are saying no one should ever do anything to make themselves or others safer if the threat is from another person. Threats from other people, from a rational, non-emotional calculation, are exactly like threats from not-people. The question is risk vs. reward.