It's good this doesn't occur in all areas, but at least for software systems (the area of vendor contracts I'm familiar with) it's not uncommon. A vendor provides an opaque system that requires relatively deep knowledge of it to perform integrations etc. A third party would need to dig deep into the system & documentation to work with it.
I've seen this with SunGard/Ellucian, and also Oracle. They would not make their documentation & technical manuals publicly available. A third party arose offering general maintenance & other services, and used customer's documentation copies to do so. SunGard sued them, and the customer [0]. Oracle has done something similar [1].
Unfortunately, this is a common practice by providers of large proprietary systems, and whether or not the vendor prevails is almost irrelevant: customers now know that competitive bidding brings a risk of costly litigation.
Personally I don't think suing your customers is a very good business practice for long term customer loyalty. Then again some industries only have the choice of a few vendors, roughly equally litigious, to choose from. The alternative is to create your own custom system, but that's an option only available to very large customers.
I've seen this with SunGard/Ellucian, and also Oracle. They would not make their documentation & technical manuals publicly available. A third party arose offering general maintenance & other services, and used customer's documentation copies to do so. SunGard sued them, and the customer [0]. Oracle has done something similar [1].
Unfortunately, this is a common practice by providers of large proprietary systems, and whether or not the vendor prevails is almost irrelevant: customers now know that competitive bidding brings a risk of costly litigation.
Personally I don't think suing your customers is a very good business practice for long term customer loyalty. Then again some industries only have the choice of a few vendors, roughly equally litigious, to choose from. The alternative is to create your own custom system, but that's an option only available to very large customers.
[0] https://web.archive.org/web/20150319233444/http://blog.thehi...
[1] https://www.chronicle.com/article/a-small-company-promising-...