Proprietary information, in regards to corporations, is basically any information that the company wishes to control the dissemination of; in addition to the fact that the company often has duties and obligations to their management and their shareholders to protect, defend, and to secure that propriety information, which is considered to be the property of that company, and often has specific penalties attached for all those that divulge proprietary information without proper permission.
So, basically proprietary information is essentially information that is secretive in nature, and often involves the restriction of a specific need to know, for those that have a desire to know. Additionally, those that have been intimately involved in the creation of, or the process of that proprietary information, even in those situations in which they as an individual basically are the ones that thought of, conceived of, and created that information, they do not own that information as individuals, whatsoever; and when there comes that time when they resign or have been excused from the company, that proprietary information remains with the corporation, and not with the original author of it.
For corporations, who are of course, the biggest defenders of proprietary information, all of the former seems to make eminent sense -- but proprietary information, while having a logical purpose behind it, is in many instances, misused. That is to say, the more information, that is secretive or proprietary in nature, but does not really need to be classified as such, and therefore fails to be publically disseminated, thus means the more information, that other companies are going to have to create on their own, and thereby often entails the duplication of efforts and expense of such, as opposed to being able to take advantage of such by working off of what has already been created, and building upon that. Further, employees that have worked with and created proprietary information, that have thereby parted ways with that company, are because of legal considerations, somewhat handcuffed in being able to take such knowledge elsewhere and therefore have to divert themselves from the pathway that they were once on.
So too, because this is a country that believes in the power of intimidation, through litigation as well as by other means, this means that information that really need not and should not be proprietary in form, are often protected as such for longer periods of time, which isn't beneficial to the public at large, though it probably is quite beneficial for that company, by precluding such. In short, as knowledge is a form of power, then quite obviously creating knowledge, and then simultaneously controlling who and what gets access to that knowledge as well as creating business models which allows corporations to exclusively benefit from that proprietary knowledge, skews things in such a manner, that often the few benefit from that knowledge, at the expense of the many.
The greatest good of mankind is never going to be served, by the creation of more and more proprietary information, in which a meaningful portion of that information has been wrongly classified as proprietary, but rather more of that information needs to be in the hands of mankind; for the concentration of more and more proprietary information into the hands of corporations, that are artificial creations, and thereby are never subject to physical death, signifies that mankind is ceding more of its knowledge to that which is not human in its structure.