Channel4’s video on demand service requires Adobe Flash Player but doesn’t work on Ubuntu 14.04 by default.
4oD relies on Adobe DRM that only works on Linux if the HAL service is running.
HAL is deprecated technology and has been stripped out since 13.10.
Luckily for us there is a PPA maintained by Michael Blennerhassett that works for both Saucy and Trusty, to enable it do as follow.
sudo add-apt-repository ppa:mjblenner/ppa-hal
sudo apt-get update && sudo apt-get install hal
Once you restart your browser, 4oD should work, enjoy!
EDIT: If hald doesn’t start automatically at boot. start it with /usr/sbin/hald (sudo not required)