All employees have a legal obligation to keep their employers' confidential information secret. In respect of "trade secrets", this duty continues after termination of employment. As confirmed by the Supreme Court, employees cannot be in breach of that duty unless they actually knew or were told that the information in question was confidential.
In Vestergaard v Bestnet a group of employees resigned from the ex-employer to set up a competing business and they developed a new product by misusing their former employer’s trade secrets. One of the employees who was the main Director of the competing company, had been employed in sales and marketing by Vestergaard and had never had access to, or knowledge of, the relevant trade secrets. In addition, she was unaware that the new product had been developed unlawfully.
The Court held that unless she knew, or ought to have known, that the actual recipients of the information were misusing it, she could not be held liable for breach of confidence.