It probably is illegal, but only if there's damages, because that is usually how civil penalties work. In a way it makes sense: how do you know they did it if y

It probably is illegal, but only if there's damages, because that is usually how civil penalties work. In a way it makes sense: how do you know they did it if you have had no damage done? The illegality is the damages regardless of how they occurred, but potentially also breach of contract if you think to specify "no backdoors" in your contract.