Conflict may arise over legal custody of children after desertion, separation or divorce, or where the parents were not married. Parents may quarrel bitterly over who is to have custody of the children and may enter into complicated legal proceedings to obtain right of custody. Having obtained it, one parent may effectively deny the other right of access and even abduct the child to this end, causing severe emotional stress to the child and the other parent. Since the grounds for divorce or separation affect the allocation of custody, parents may indulge in defamation of each other's character. In many cases there is legal discrimination against men. In the event of desertion or illegitimacy, the custody of the children weighs against the single parent who may have sole responsibility.