Law Student writes: "I'm a law student taking an intellectual property course at the University of Texas at Austin. I've recently learned that in order to prove copyright infringement in a civil suit, a plaintiff need not establish that an alleged infringer knowingly copied the protected work in question; rather, unknowing copying is enough. This obviously puts something of a burden on creators of new works to ensure that their purportedly new works don't infringe upon pre-existing copyright. I've written some lyrics to a tune I also wrote. My gut reaction is to google phrases from the lyrics in quotations to test their originality. However, I'm hesitant to do so becuase I'm not sure whether Google might have a valid claim of ownership (worst-case scenario), or whether those lyrics might arguably pass into the public domain once submitted (not quite as bad). Any IP attorneys or others out there who could shed some light on this issue?"