Vendors Can Control Software Use

Microsoft in Visual C++ 6.0's MFC library included a clause preventing the use of the software to develop programs for a non-Microsoft OS. This restricted what a user could use this system for in a totally artificial way.
Under UCITA these become legally enforceable.
Microsoft fortunately changed this license in a subsequent Service Pack Release (SP3)

Microsoft in Visual C++ 6.0's MFC library included a clause preventing the use of the software to develop programs for a non-Microsoft OS. This restricted what a user could use this system for in a totally artificial way.