Well drafted contract clauses can help to protect an employer by deterring detrimental action. Poorly drafted clauses do the opposite as employees will be advised that the provisions will not be upheld, perhaps because the ambit of the restriction is too wide.
It is vital for employers to consider their objections and seek appropriate drafting advice at the time the contract is entered into (or amended) to ensure that their interests are properly protected. In the event of a breach of confidentiality, a breach of post termination restrictions (such as a former employee soliciting clients) or intellectual property theft swift action is essential to stem the damage. Sometimes there is no choice but litigation, even if to act as a deterrent to others, but overall it is much better to prevent the damage rather than seek compensation after the event.