When downloading, printing out, or sharing published articles, it is your responsibility to stay within Fair Use as defined by US copyright law:
When using our site-wide databases of published articles, this generally means that you may reproduce an article for your personal use, or distribute it within a limited work group, for purposes of noncommercial research.
When you request articles through the library, we pay as needed to make sure that copyright law is upheld. Unlike articles from our site-licensed databases, these are only for your personal use, and may not be shared or reproduced. If you need wider distribution, please contact the library.
If you systematically download large portions of published material, download more than one article from a single journal issue, or more than 10% of a single book, this may be in excess of Fair Use, and copyright fees may be due the copyright holder. This is necessary even when your purpose is non-commercial research. The Copyright Clearance Center offers an easy way to pay copyright fees online with a credit card.