True! And while I've never heard of someone getting in trouble for using a newspaper headline or text, it's just good to be aware of the issues surrounding copyright. These are the basics that I know:
1. Once I create it, it is mine, whether or not I register it, and I have the right to determine who else can use my image and for what purposes.
2. Unless I register it, I cannot sue someone else for damages, though I may be able to enforce a cease and desist.
3. I don't spend a lot of time worrying about it!
Anything published before 1923 is in the public domain, so I look for books and images prior to that to use to supplement the photos I take myself. Many many people here use small snippets of modern magazine and other images/text. A single eye is not highly likely to be really recognizable and to get one in trouble. But I just prefer not to do it. Personal choice, not a morality lecture