30 Every one who witnesses a breach of the peace is justified in interfering to prevent the continuance or renewal thereof and may detain any person who commits or is about to join in or to renew the breach of the peace, for the purpose of giving him into the custody of a peace officer, if he uses no more force than is reasonably necessary to prevent the continuance or renewal of the breach of the peace or than is reasonably proportioned to the danger to be apprehended from the continuance or renewal of the breach of the peace.