Auditors are often are called on to assist with software audits and
some are confused over the steps needed to be taken.
See http://www.pcprofile.com/Proof_Of_Purchase_Really_Means.pdf
for
some views on the topic.
With the antipiracy vendors (BSA, FAST, CAAST, RIaA, MPAA, etc)
stepping up their campaigns its best to be one step ahead of them.
