Turning on bce in screen avoids padding the screen with trailing spaces,
which makes copy+paste a lot simpler. It does not work simply by turning
bce on, however, it also needs a termcap that tells the applications
about this. In Fedora, this termcap isn't installed by default, you need
to install the ncurses-term package, once you do everything starts working
(to turn bce on add defbce on and term screen-bce to your screenrc).