I intervened once. It was at a bar and I saw a guy outside slapping his gf/wife around. I went out and stopped the guy. He took a few shots at me and I just pushed him back as I got the girl to come back into the bar with me. The bar owner and a buddy of mine then made sure the guy was not coming in. After a few minutes he got in his truck and left and a couple women in the bar sat the gf/wife down and tried to relax her and all. She was pretty shaken up by it, obviously.
Well, MY Gf wasn't too happy about it. She hated that it could have went really bad for me and thought I may have been a bit reckless. I didn't think so at all, but later that night I realized that this woman is eventually going to go back home and nobody would be there to "protect" her when she did. So the reality began to sink in and all I could do was watch the news and hope that she wasn't in any story the n ext day.
It's tough to say what I'd do if I saw a man getting beaten. I'd obviously call the cops, but I am also licensed to carry a concealed firearm. If I saw a man who was being beaten to death, that would be a tough call. Legally I'd be justified to use it to protect somebody like that (either by drawing it or actually firing it) but that's something that I don't ever want to have to even consider. That's why I stay away from bad areas, stupid situations and idiots. The days of going to bars or hitting the city and walking 8 blocks to see a show are long gone.