They chose to rent there. No one forced them. They have to obey the rules of their rental agreement. You don't want to have restrictions on what you do, pay more attention before you sign a rental agreement, join a co-op, or buy in a gated community.
Tempest in a teapot. Another fool who thinks "the rules" don't apply to them just because they are a veteran. And no, serving in the military doesn't make them more American than anyone else here or entitle them to disregard the community rules that they agreed to by renting in that community. Same sort of story turns up in the news every Memorial Day, Fourth of July and Veterans' Day.