After scripts meant for translation somehow made their way to the internet, the BBC is asking fans not to spoil the 5 episodes that are floating around. In a statement to RadioTimes, they said:
BBC Worldwide is currently investigating a security issue around Doctor Who Series 8 where unfinished material has inadvertently been made public. We deeply regret this and apologise to all the show's fans, the BBC and the cast and crew who have worked tirelessly making the series.
We would like to make a plea to anyone who might have any of this material and spoilers associated with it not to share it with a wider audience so that everyone can enjoy the show as it should be seen when it launches. We know only too well that Doctor Who fans are the best in the world and we thank them for their help with this and their continued loyalty.
If you don't want to see them, be ever more vigilant. SPOILERS EVERYWHERE.