It's not obvious from the LWN article, but the reason it says "White House" is that lawyers from the DoJ have filed an Amicus Curiae ("Friend of the Court") brief informing them of their stance on the topic. [1] [2] [1] - http://arstechnica.com/tech-policy/2015/05/white-house-sides... [2] - http://cdn.arstechnica.net/wp-content/uploads/2015/05/google...
Is the term "White House" often used to refer to anything within the executive branch? I have always assumed it meant the office of the President and perhaps his cabinet...
Only when people are being sloppy, either through ignorance, or, e.g, because its convenient for spin they'd look to put on something.
Less sloppily, referring to an entity rather than a building, it refers to either the White House Office within the Executive Office of the President, or the whole Executive Office of the President (both of which are headed by the White House Chief of Staff.)