Leaving aside the obvious ethical issue here, what's the solution? Don't do mashups? Or, do mashups in a moderate way so that you are only providing limited quo

Leaving aside the obvious ethical issue here, what's the solution? Don't do mashups? Or, do mashups in a moderate way so that you are only providing limited quotes of the originating site and providing attribution? Or, say to hell with it, I'll do what I want and only worry about legal problems if I get big enough that someone comes after me?