This is a situation you often see in life. There have been campaigns on TV and all over the internet. Domestic violence is no joke, and it often goes unreported. Despite what you think however, the main victim of DV are usually males. Females tend to think they are allowed to hit men without consequence, and it often goes unanswered in the privacy of the home.
However, that does not mean there are no female victims. As females are physically weaker, they tend to be an easier target for the insecure “alpha” males who wish to vent their frustration on someone smaller than them. When you see someone doing this in public, it is not illegal to physically restrain the culprit. It is an entirely different story when it is an unprovoked attack.