Upstream issue: https://github.com/rg3/youtube-dl/issues/3104 Fixed in 2014.06.19, but I'd suggest updating to the latest 2014.06.24.1 as long as we're updating it anyway. Thanks!
Fwiw, I've hit this on many but not all videos; here is one example: $ youtube-dl 1YHIV4a81Os
youtube-dl-2014.06.24.1-1.fc20 has been submitted as an update for Fedora 20. https://admin.fedoraproject.org/updates/youtube-dl-2014.06.24.1-1.fc20
youtube-dl-2014.06.24.1-1.fc19 has been submitted as an update for Fedora 19. https://admin.fedoraproject.org/updates/youtube-dl-2014.06.24.1-1.fc19
youtube-dl-2014.06.24.1-1.fc20 has been pushed to the Fedora 20 stable repository. If problems still persist, please make note of it in this bug report.
youtube-dl-2014.06.24.1-1.fc19 has been pushed to the Fedora 19 stable repository. If problems still persist, please make note of it in this bug report.