I think you're misunderstanding their theory of why it would be bad? In the example where a hedge fund buys information from Best Buy about how many Panasonic

I think you're misunderstanding their theory of why it would be bad? In the example where a hedge fund buys information from Best Buy about how many Panasonic TVs they sell, Best Buy may have a duty to Panasonic, and thus are an insider in that context, so if the hedge fund buys that data from Best Buy, they could potentially be trading on insider information. It's not because they own the stock.