Short answer, yes it is legal to ban someone that has donated or bought a rank from your server, it is there chose to support the server and most servers have a way to reward players when they support the server so there for the money is going into supporting the server not rewarding the player even if they get rewarded so it is completely legal to ban someone who has donated ranks do not mean players are entitled to breaking the rules
I'm answering this because its commonly asked on different web pages
Short answer, yes it is legal to ban someone that has donated or bought a rank from your server, it is there chose to support the server and most servers have a way to reward players when they support the server so there for the money is going into supporting the server not rewarding the player even if they get rewarded so it is completely legal to ban someone who has donated ranks do not mean players are entitled to breaking the rules
I'm answering this because its commonly asked on different web pages