Emily Dresner-Thornber reminded me of one of my favourite illegal financial mechanisms, the tontine.
In case you're not familiar with it, the tontine is a group ownership of some item. As each person dies, his or her shares pass to the other survivors. Whoever is left standing at the end, owns the whole thing. Very useful if you want an excuse for murders galore.
In a powered person context (because clearly this isn't going to be about superheroes, just supers), all powers derive from one power source. Originally, all of ten thousand people had powers. (In a supers game system with points, everyone had the same low number of points.) But if you kill someone, you get their points. When you have children (if you have children), they get your points. There's a trade-off: more kids means that someone is likely to survive, but they probably each get fewer points. And you're stuck with fewer points. Some powers, like immortality, let you avoid losing points under normal circumstances, but if you have kids, you're unlikely to be immortal....they've sucked up your points.
The contest to kill other super-powered people starts. I think it would start as overt, but as members got better, it would move to covert: some people would hide. Once individuals get past a certain point, they might be overt again. ("You killed that guy, and then your skin started glowing. Weird.")
There's an interesting situation where some very low-level supers had kids and essentially became invisible because everyone had so little power. And then the parents die, and the kids get stronger. So they get attacked. Maybe it's luck, maybe it's the fact that their parents took someone out with a rocket propelled grenade just before they died, but all of a sudden, the kids are in this decades or centuries-long game and they have to survive. And folks aren't going to leave them alone.