Jason always knows the right people to kill. He said, 'You know the first question you ask in any murder case? Did the victim deserve to die?
Normally when something bad happens to an individual you feel some degree of pity for them. But then when that person is a Jerkass or an outright monstrous villain, when horrible things happen to them it's less sympathy and more satisfaction.
They may or may not be directly responsible for their misfortunes , but their behavior means something like this was going to happen eventually. The victim may just be a dick, or they may be a far worse criminal than the offender. If there is a correlation, the response may or may not be disproportionate , but when a victim-shaped hole in the plot is filled with a sufficiently repugnant character, it's unlikely the audience will feel bad about it.
The character doesn't have to die or be brutalized; in some cases, "victim-shaped hole" can mean "victim of non-violent theft," so long as they're victimized in some way, for no apparent fault besides ignorance of the danger they were walking into or misjudging the situation.
If they're able to confront their attacker, there is a high likelihood they have no idea what earned their ire. This trope can show up for a variety of reasons, but a common one is to make the criminal or Non-Malicious Monster into a Sympathetic Murderer. This is especially likely if the Asshole Victim's dickery is what motivated the criminal to commit the crime in the first place.
