Despite negative connotations "hacking" still means expanding the usage of an object and "terrorism" still means enforcing ones ideals through violence.
So these comparisons are not valid.
EDIT: To make my point clear. When clicking the link, I thought the article was literally about pirates, that is sea criminals (or perhaps the political party). If only the author would have used the more descriptive, and more correct term "copyright infringement" I would have been less confused. So usage of the word "piracy" in this context is both damaging, wrong and confusing.
I really liked Rebecca's approach, because rather than getting into a rage about her book being ripped off, she kindly, and politely explained how they are hurting her, and what the consequences are for those who enjoy her writing.
For further reading of why Amazon is bad for authors and customers alike, see: http://stallman.org/amazon.html