If what you do with a copyrighted work is covered by fair use it doesn't matter what the license says - you can do it anyway. The GFDL imposes restrictions on distribution, not copying, so merely downloading a copy imposes no obligation on you and so isn't a copyright infringement either.
I used to be on the FSF board of directors. I have provided legal testimony regarding copyleft licenses. I am excruciatingly aware of the difference between a copyleft license and the public domain.
I used to be on the FSF board of directors. I have provided legal testimony regarding copyleft licenses. I am excruciatingly aware of the difference between a copyleft license and the public domain.