As a hypothetical situation, let's pretend that Free Republic is an illegal music site. Here are two examples to illustrate the difference -
Legal: http://www.freerepublic.com
Illegal: http://www.freerepublic.com
Both of the lines above contain similar information, but the second line has a link that actively functions as an infringing device.
Of course, the user could simply copy and paste the URL in the first line into the browser's location box to arrive at the same location - but that line is simple text protected by the First Amendment.
That simple distinction could easily be wiped away by another judge...
Interesting information. Thanks.
And the second is the backbone of the Internet.