Spider Robinson wrote a great short story about someone going back in time to prevent Heinlein from contracting tuberculosis-- to prevent the invention of science fiction! Things don't work out as planned, of course.
I can't find it right now, but I did find a really great story he wrote about copyright law. It won a Hugo award. I can't believe I hadn't read it before today.
http://www.spiderrobinson.com/melancholyelephants.html