The big difference is Facebook pages are public, or at least semi-public.
If you go through the e-mail account or texts of a spouse or close friend, you're engaging in a massive breach of trust, and better expect to have them break up with your or refuse to deal with you going forward.
Likewise, the US will now have to face the expectation that US diplomats can not be trusted with any kind of information, including phone numbers that may previously have been considered "safe" to give to allies.
Especially since the document made clear that the NSA did not know all the numbers, hinting that cycling numbers and keeping numbers from US diplomats may still be a viable strategy to reduce the odds of having your calls monitored.
If I was in a position of power now, the first thing I'd do is demand that all senior government officials change numbers, and allocate a wide range of different numbers per person, and allocate one set for the exclusive use for giving to US diplomats and communication that I want the US to pick up, and cycle other numbers frequently and compartmentalise their usage more, since it is clear that the US can not be trusted.
