Re: Facebook's statement doesn't actually say they support Apple and Tim Cook...
You can only claim that there is no intention to expand the scope of this when you fully ignore what kind of precedent this sets. As an aside, Facebook proclaiming any interest in "security" was worth a laugh, but I'm going to park that for the moment.
This order asks two things.
Directly, it demands that Apple develops a backdoor (note that there are no statement on feasibility here either). Strip all the limiting waffle off the order, and this is what is being asked. Yes, it's "only once" and "only for these really bad people and oh my God think of the children" (an argument that we see time and time again when the asker is not certain that pure facts will be enough to get their way - always a red flag IMHO), but FBI + judge have really bent over backwards to make people ignore that fact that that is simply not how US law works because ...
INdirectly, because of how US law works, it would establish a precedent that the FBI (or anyone else who has sway with a judge) can demand a successful company to commit commercial suicide by reverse engineering the very security they have spent many man years developing and go public that they have done so (remember, this is about evidence that is eventually used in a public court of law). That precedent, by the way, entirely nullifies the claim of "we'll only ask for it this once" because it establishes in law a path to a repeat performance. "We did it here successfully already, so we can ask for it again here, Your Honor." Given that this order has been issued by a judge, it would not be unreasonable to assume this judge knows this full well, and it is thus worth keeping an eye on this person because I'm rather intrigued by their motivation.
This is what is really happening. It is not really about Apple, but I assume the thinking was that if they got Apple to cave, the rest of the industry would follow and they would finally have their much desired mega backdoor.
What will happen next if the FBI is successful is easy to predict: just look at what happened to the physical luggage backdoor the TSA demanded "for your safety". It's been used by thieves to empty your luggage of valuables quicker than New Labour emptied UK's Treasury, and you can even get 3D files to print those master keys in the comfort of your home. In short, you can kiss your security goodbye, and Silicon Valley would formally be declared as worth avoiding by EU business as it would lead to non-compliance with EU Data Protection laws - already a distinct possibility if Privacy Shield is not given some more legal teeth.