Collateral damage

[Michiko]

When someone is having major [issues] in their life that are totally unrelated to you but for some insane reason they are [taking it] out on you. You are now [collateral damage] in a fight that they should be having with someone else.

[Dave Paprocki]

during a war, the unintentional deaths and injuries of people who are not soldiers, and damage that is caused to their homes, hospitals, schools, etc.