John Tehranian has a great article on why perfectly innocent acts can still add up to "copyright violation":
Yet amidst the flux, one constant emerges: the 1976 Copyright Act lies always at the heart of these debates, inextricably mediating our relationship with cyberspace and new media. Three decades have passed since the current Copyright Act went into effect. Without dispute, tremendous economic, technological, and social changes have occurred in that time. And although these changes do necessarily warrant concomitant reform, this symposium follows on the premise that we have reached an appropriate point to evaluate the efficacy of the extant Act and think holistically about the issue of reform.
At this juncture, three key trends bear close observation. First, copyright law is increasingly relevant to the daily life of the average American. Second, this growing pertinence has precipitated a heightened public consciousness over copyright issues. Finally, these two facts have magnified the vast disparity between copyright law and copyright norms and, as a result, have highlighted the need for reform.