Public Relations - how they are perceived by the public. This was seen as a risky move because it had the potential (which Facebook realised and decided to press ahead with anyway) to anger a lot of people.
Public relations -- bad press. Here's some more context from the BBC article:
> Facebook had been aware that an update to its Android app that let it collect records of users' calls and texts would be controversial. "To mitigate any bad PR, Facebook planned to make it as hard as possible for users to know that this was one of the underlying features,"
https://en.wikipedia.org/wiki/Public_relations