I agree we have to talk about being vulnerable but if someone told me they were thinking of being violent towards me, I dont think it's unacceptable for me to safeguard against that. I would happily talk to them until the cows come home but whether I would start a relationship with someone expressing violent feelings is another question. I understand that everyone has violent urges from time to time but not everyone has such urges towards people they do no know. The only time I've had violent urges is during a huge argument with someone, never to a group of people in general. A person feeling this way could have a lot of bottled up anger after years of repression. Unpacking that can take time, even with a therapist (nevermind a relationship, which can at times be emotionally stressful). Addressing such feelings takes time and a lot of self-reflection. A relationship could be a barrier to that