Ah, I was proposing the "turn an aspect into a character".  Their example also indicates you should give it unique stunts (that don't have to be balanced with book stunts) to represent what it does.  Of course, the vast majority of the time the players should know how it works mechanically -- this is especially true with something like a bright light.

So, to specify further, with regards to the light, it would look something like this:

Bright Light  (An aspect)
Skill 2  (This is used for defense, offense, and whatever else it actively does)
Stunts

• No Shadows: Anyone making a check to see an something the light illuminates, gains a +2 bonus on the roll.
• Tiny:  +1 Defense again non-area attacks
• Device:  Hexing can be used to make attacks on this aspect.

Stress Boxes: 2

That would be the general idea, though perhaps you'd lower the skill level to 1 or modify the "No Shadows" stunt.  Destroying the Aspect would represent breaking the light (hence the "device" stunt).

Again, I'm not saying this is for everyone.  But for some people/groups the normal aspect approach here could break their willing suspension of disbelief and/or they could find a compel an annoying way to handle the situation (the above fractal provides options a compel wouldn't, imho).

Woah, are you saying Mouse can't meaningfully interact with mundane humans?  I think he does a pretty good job.  He's certainly more popular than Harry.

It's certainly a challenge, I'd admit, but there aren't any special abilities granted by the rules.  The most annoying thing is probably not being able to talk if you look like an animal.  If you don't, then you can get more meaningful interaction, since you can talk (you just have to set up a disguise right).

Hmm, one idea is use the fact you have to hide who you are as a compel against your High Concept.  That should get you a lot of Fate Points at least.

Overall, I think Mouse would be pretty fun, though it seems like a bit of a waste to have good deceit and rapport scores since you can't talk -- they've be great for manipulating people in the manner Mouse does.  Maybe Fate Points would be enough to bridge the gap there...I'm not sure.

Additionally this is the very thing that the OP is asking for. How can I represent a situation under which all of my magic is shut down? Seems odd to rail against the goal of the post itself.

I only meant that an IoP does this better than just an aspect.  A pure aspect would have to say one thing and mean a host of other things, unless it is going to be "All my magic power is in me bag o' bones" or something.  Yes, you can certainly make it so it works that way and so everyone understands it.  However, I do not think it is terribly elegant when you want to also have all these crunch aspects too.

An item that has powers attached frankly screams IoP, and it is simply enough to modify the base IoP rules to get it to work perfectly.  It would be like making a vampire, and instead of taking Hunger, just taking an aspect to cover it.  The result is much more crude.

If you go the magic computer route, then I think that's a little Archive Magic plus some AI.  Obviously it would have to be much, much, much weaker than the actual Archive.  However, something that can remember any book you show it or even potentially search the internet should be possible.  It seems like creations with a bit of intelligence are possible in the Dresdenverse -- there are constructs of various sorts that show rudimentary intelligence and that's a lot more than what computers can do.

So I think you could certainly talk to a GM and come up with a good idea for a Magi-"tech" library that can search through any book you have or potentially remember any book you show it.  That's maybe even just a few power to do, since 10 shifts would be enough to store a lot of information (if you consider it a type of knowledge or lore check).  If you wanted to go with overkill, then 20-30 shifts would easily hold all the information on anything -- though you might still have to go out and find that information to feed into the system.  After that you just need duration.  I think interface is largely flavor, but you could always add a few more shifts to speed up searches and the like.  A really Great Library might be 50 shifts (maybe 60 or 70 for a really, really long duration unless your GM makes extending the duration at a later date easier), which IS a lot, but also something that could be fun roleplaying out over many sessions as you slowly put all the pieces together.  Or you could start smaller with a more limited library and just do like 15 shifts for a narrow focus.  This would still have limited access to information, of course, since you'd be lacking all the symbolic links, but I think that would be more than enough to justify letting it automatically add in any book you come across.

AI is a bit more difficult to figure out how much it should cost.  I suppose one method they've recommended is acting like it is a creature you were killing and look at the total refresh, double that number, and maybe add a bit extra.  So 20-30 more shifts should be pretty good for that before duration considerations.

All said, to make a Bob we're probably talking about spell that requires 100-150 shifts.

Edit:  Regarding the tech-based solution.  I think it is safe to be pretty lenient if a player wants to do something like this.  There's really not that much powergaming that could potentially be done in the Dresdenverse with a computer.  It isn't like you can hack into a Denarian and control them.  Really you are just getting games, the internet, email, etc.  Heck, even if a Wizard never hexed anything, it isn't really a significant power shift.  Guns?  They can use plenty already since there are tons of very effective old guns from WW2 (and others of similar complexity that are more modern).  A better car isn't going to change anything.  About the biggest difference is a cell-phone, and that won't change all that much.  In the end, accidental hexing is a lot more like flavor than anything else (and occasionally a source for fate points).

My take is, the circle can be broken by anything (or anyone) it is trying to protect or prevent.  Draw a circle around yourself to keep the bad guys out and you'd better not let a finger cross the line.  Draw a circle to keep a demon in and you'd better not let anything it can use or become cross the line.  Draw a circle to keep electronics safe and you'd better not let any electronics cross the line...

By that reasoning you are also making a ward to protect kids, since it BLOCKS MAGIC.  The ward isn't focused on electronics in its design, it is focused on stopping magical energies.  A ward to protect a house similarly protects your bathroom, but that doesn't mean the plumbing cancels it out.

I think that's sufficient, though I'd also note there's a difference between electrons moving a little bit and electronic devices maintaining their physical status.  The two are very different, if related.

Don't forget you can do more than just invoke an aspect for a one time bonus.  Take the long range cover situation you mention - I'd invoke Behind a Wall for effect and leave the shooter unable to Target me at all until he maneuvers to void the aspect...or until I do something which ends it. 

Fate supports standard tactical tropes, it just does so by modifying the narrative instead of the action.

I think you are getting Aspects On The Brain disease (happens to us all).  You don't need an aspect to stop someone who can't see you from shooting at you, and you certainly don't need an invocation.  The other guy is the person who needs to justify shooting at something that he can't see, especially if they are behind a bullet-proof object.  Anyhow, I meant cover as something that you still exposed yourself a bit from to fire/attack...if you are just hiding behind it out of site, there's no need to use anything for that (unless the enemy has the firepower to destroy the cover, in which case a Fractal works best since it would have stress boxes).

I proposed using fractals just because that's something that has already been brought up as an idea for some things.  It would work fairly well, I think, and there are lots of ways to handle them.  Note that aspects are NOT used for a large number of things in the game, because aspects don't handle lots of things well.  You don't use Aspects to represent Zone Borders, for instance.  They also aren't very granular.  An Aspect for a Zone Border wouldn't make much of a difference between a 4' fence and a 10' fence; using something with a raw number does, and this sort of gross distinction does matter for the story.

There's another way one could have that fractal work for a light as well.  It could have a stunt that says "Stealth Roles at a Result equal or below the skill level of the Light fail" That's probably a better way to go, kind of like a reverse Veil.  I think using Fractals like this makes a lot of sense; obviously players should be informed how any Fractal works if it is stuff they should know (such as with a light).

Again, I am not saying all groups should do it this way.  I am just saying that some groups are going to have much bigger willing suspension of disbelief (WSoD) problems if you handle everything without a unique mechanic using aspects.  WSoD problems, when they crop up, can easily damage the game by undermining the narrative impact.

You could do that, but it's just adding the whole concept of modifiers that the aspect system is trying to replace. Of course the issue of constantly on aspects is something that trips a lot of people up. Fred once explained it though. FATE is a very story based game. When no one spends a fate point to use an aspect it's just not important to the story at that moment. It's still there, it just doesn't effect the outcome. So in the "brightly lit" hallway, if no one spends a Fate point the hallway isn't dark, it just doesn't matter that it's "brightly lit." The player was clever enough to distract the guard, or the guard was briefly (or not so briefly) inattentive. If someone does spend a fate point then it becomes important. The guard is paying attention. The player is trying something that is less then effective under those specific circumstances (I.E. in a "brightly lit" space), etc.

I do not think aspects out of the book handle everything in a perfect manner.  However, what I proposed could work well for some groups and it doesn't mean you can't distract the guard.  A maneuver that cancels out the effect of that aspect/fractal should logically then prevent it from helping anyone out.  So if you distract the guard, then he doesn't gain the bonus of a well-lit room.

This isn't the best way to handle everything, but aspects DO have problems in some more extreme scenarios.  Hiding behind cover from someone shooting 100 yards away.  That cover only being there when powered by fate points is danged peculiar.  Some thing with guards who just have to look down a narrow hallway that has good lighting.  The latter is especially true if the guards are not human and don't get distracted -- though honestly, getting distracted a bit is handled fairly well by dice rolls and maneuvers.  Similarly, if you are standing in the middle of a burning fire, then "the zone is on fire" as an aspect IS a bit lacking.

These things can overly stretch or even break the willing suspension of disbelief for some people, and so some groups might want to look at ways to modify the game to handle it.  I think going with a bunch of situational modifiers for lighting, fog, etc, etc, etc like D&D and other games have is not the right way to go.  However, some aspects with a little mechanics tacked on can fill in here in these particular extremes if the group finds it more satisfying and fun.  Fractals are useful in this manner.

Not all IoPs need to be unbreakable; hexenwolf belts are an example of one that isn't.  There's certainly no reason to be bound to some relatively minor details like that or even the more minor one that the IoP has the power inside it.

My only concern with an aspect is that while yes, you can take compels to not be able to use magic, overall I just don't see that coming up that much.  So it might not make for a very interesting aspect since it isn't a very fun compel since it shuts down all of your magic.  I'd think GM and player both would tire very quickly of the idea of the bones getting taken away.  I'm just saying another aspect might be more fun.