[bluGill]

> On what grounds do you have no right to use a copy of software you bought without obtaining an additional license from the vendor

To use software you probably have to install it on your computer - this makes a copy of the software. Then when you run it you make another copy into your computer's memory, and additional copies in the the CPU's cache.

I don't agree with the above argument (I think fair use covers it), but I have heard it. It isn't hard to read the letter of the law and conclude the above is the correct interpretation. (you might need to see some money...)

I honestly do not know how to fix the letter of the law. There are too many special cases. If I have two computers can I install it on both? Can I install it for my family to use? When my computer fails can I install it on the replacement? The above are trick questions: I deliberately asked them to invite answers that imply I can install one copy of software on as many servers as I want for as many users as I want - this seems wrong.