George Orwell's Politics and the English Language (which should be required reading for everyone) has a section titled "Meaningless words" which contains this wonderful sentence:

"The words democracy, socialism, freedom, patriotic, realistic, justice have each of them several different meanings which cannot be reconciled with one another."

I try to keep it in mind whenever I see someone mentioning freedom, openness, rights, etc. Generally it seems like these are used for emotional appeal rather an actual clear definition.

Edit: Link to the essay. It's short, and very well worth the read. http://www.mtholyoke.edu/acad/intrel/orwell46.htm