word games

[dchenes]

All jokes about sick birds aside, what exactly is the difference between "unlawful" and "illegal"? I get the impression that for something to be illegal, there specifically has to be a law against it. "Unlawful" seems to have a moral or social, rather than legal, connotation to it. So the government wiretap program is unlawful to begin with and has just been found illegal besides. Am I right?