How, precisely, does this information do "serious damage...", as you say. We already knew that the NSA can hack computers and cell phones; the article is simply more of the same.
I'd say any specifics – size, people involved – on such a program could be damaging, and it also gives other nations more ammo in defending their own such programs, by pointing out ours. I know everyone already probably knows we have things like this, but it's even more public now. They also talk about a document in there revealing the specifics of counter-surveillance for the Bin Laden raid.
So "serious" damage is probably too far. But how does this benefit the American people? The US has pretty good reasons for keeping such an effort covert, and this stuff doesn't come across as an affront to people's privacy and freedoms, not like the domestic surveillance programs did.
So "serious" damage is probably too far. But how does this benefit the American people? The US has pretty good reasons for keeping such an effort covert, and this stuff doesn't come across as an affront to people's privacy and freedoms, not like the domestic surveillance programs did.