Hold up -- Angel investors give you money in exchange for equity. That's usually how it works. Are you saying that instead of giving money, these angel "investors" are executives a major companies who are trading customer deals at the company they work for in exchange for personal equity? Or are you just saying that they invest their money and provide connections in addition to their money?

In the primary situation, they are benefiting by getting stock in exchange for giving their company's business to the startup (illegal kickback). In the second situation, they're referring companies they have a personal financial interest in for business to enhance the value of their investment (conflict of interest).

Need more specifics.