"Often people are hired for a job on the strength of what they have learned working for a competitor. The assumption, often unstated, is that the new-hire will bring specific knowledge of their former employer’s competitive advantage. In this situation, it is permissible to bring general knowledge of a competitor’s business to a new employer. You will have signed a legally binding employment contract with the first employer, and this prohibits the disclosure of any proprietary information to a third party without written permission. So you must not make copies of commercial-in-confidence material, and especially not sell that information to competitors, whether directly or by going to work for them. Severe penalties apply for proven breaches. A recent press report describes how a man was sued by his former employer because he took with him 17,000 followers of a promotional Twitter account when he left. The former employer alleges that each follower is worth $2.50 and was seeking damages. The man was working for a competitor by this time. Intellectual property protection or copyright applies to specific implementations of an idea. It is the implementation that is copyright. Organisations can try to patent or copyright an idea, but it is often problematic. An abstract idea can be implemented in any number of ways. If the implementation is sufficiently different from the original then copyright breach cannot be proven. The history of innovation is full of instances where good ideas have been thought of independently yet simultaneously. The underlying idea might be similar, but the way it is implemented will differ significantly."