The DIS has posting rules that apply to all users. If any poster violates these rules they can lose their posting privileges. This is especially true when someone has been given multiple warnings and continues to violate posting rules. Most often other users do not see the specific posts which violated rules as those posts are removed immediately.
In some cases, once a user has lost posting privileges under a specific username, they will create a new username to get back on the boards. That new name is denied posting privileges as well.
Since the OP's original question has been answered, there is no further need for this thread to continue and it is being closed.