Original sentence: Computer companies, therefore, used licenses to prevent unauthorized copying.When the federal courts interpreted the Copyright Act to give computer programs the same status as literary works, companies continued  to license their products for end use to avoid transfer of their copyright to the end use via the doctrine of first sale (see Step-Saver Data Systems, Inc
Edited sentence: To protect their future income, commercial computer companies used "licenses", contract terms to augment the legal rights of trade secrets, to prevent unauthorized copying.When the federal courts interpreted the Copyright Act to give computer programs the same status as literary works, companies continued the practice of "licensing" their products for end use to get around the doctrine of first sale (Step-Saver Data Systems, Inc