"There are certain people that are marked for death. I have my little list of those that treated me unfairly"

This quote by Jennifer Lopez recommends that she has experienced mistreatment from particular individuals in her life. She indicates that she has kept a mental list of those who have actually mistreated her, which she thinks they are "marked for death" in some way. This could mean that she is seeking revenge, or that she thinks they will ultimately deal with the repercussions of their actions. It might likewise be interpreted as a metaphor for the concept that those who maltreat others will ultimately deal with the effects of their actions, either in this life or the next. Whatever the case, it is clear that Jennifer Lopez has actually experienced mistreatment and is not going to forget it.