Any party should be allowed to sue any other party without any limitations. Parties should be allowed to sue any other party vertically or horizontally across any hierarchical structures, across any political boundaries, and without restrictions of any kind. People could sue animals, Martians, or the Moon if they so desire. Of course, they will be required to pay all court costs since they are likely to lose such cases. Contracts should not be allowed to limit people’s right to sue in any way.