To a first approximation, I think we'd see similar events to those of High Wizardry. The internet wouldn't have a planet of computronium to build stuff out of, but it would have access to all our networked machines. That gives it control over most modern cars, most satellites, a lot of factories... plus the entire global communications network, obviously.
I have to think Wizternet wouldn't much like what it sees. The Oath tells it to 'guard growth, ease pain', and protect life - but humanity as a whole is terrible at those things. And now the network which controls everything knows that...
Okay, so. What's its first priority? Let's check the leading causes of death in the world.
#1 through 7 are all diseases of various kinds. Most of them are treatable. Wizternet controls the factories for the treatments, but doesn't really have a way to get the treatments where they need to be. Wizardry? A hundred thousand tiny 'move this thing to that car' spells could go a long way here. It also has our medical records, so it can deliver boxes of medicines to everyone who needs them, free of charge.
Outside the developed world, things are a bit more tricky. Wizternet's observation is much patchier, and it doesn't have the resources available. On the other hand, the top causes of death are respiratory infections and diarrhoeal diseases, which are extremely treatable, since they mostly go away with food and water. So leave the medicines (for now) and divert all that food being shipped everywhere to where it's needed. This will also deal with malnutrition, and thus guard growth.
Moving on, the 8th cause of death is road injury... and Wizternet controls the most recentcars. They're being used horribly inefficiently - if people only had a car when they needed it, we could probably get by with a tenth of the number. So here's the plan:
-On every networked printer worldwide, print out simple instructions for how to call for a car. (Basically 'speak in any microphone'.)
-Take control of the networked cars. Use them to disable the non-networked ones. This may involve a lot of crashing into parked vehicles, though anything in a wirelessly-controlled garage can just be locked in.
-Run the networked cars as massive single-player Uber.
The rest of the top 10 is diseases, but there's also a whole bunch of shooting going on... plus a whole bunch of networked drones. Since this is direct, purposeless death and maiming, a huge violation of the Oath, Wizternet gets to take control of the drones and use them to steal or smash every weapon it finds. (Hunting weapons are not excepted - it doesn't say 'human life'...) This may involve injuring their wielders, if they're currently in active use - that's a shame, but within the limits of the Oath.
So: growth guarded, life protected. What are its next priorities?
-Self-protection. It needs to be able to keep itself online. It also needs more mobility, so it starts a rapid evolutionary robotics program across any suitable factories. It should only take a few days to come up with a primitive mobile.
-Bring wizardry safely into the open. Wizternet knows about Earth's other wizards, and also knows that quality of life is much better on planets where they operate openly. Human wizards can't make that change without causing widespread upheaval - but Wizternet is already doing that, and is ideally situated to keep a lid on things until it passes.
-Direct quality of life improvement. At this point Wizternet is going to run into a huge problem: its views of what humans (and indeed organics) like are coloured by what's uploaded to it, and a whole bunch of that is X-rated...
hS