It's more ideal to build the ban duration up over time instead of instantly permanently banning the player... especially when the player isn't even doing it on the server, the player won't know what he / she did wrong.
I honestly don't think you should be banning, muting, or gagging someone who is making bad decisions out-of-game. The person will just join the server, find him/herself banned and will have no clue what even happened. If we punished everyone for something they did whilst they weren't in our servers, we'd all be banned by now, including me.
Unfortunately it would be illogical to bring a player who is breaking a rule that is not universal (such as hacking) to be banned upon. People act differently in different atmospheres.