That is somewhat limited…. although there is a reason why I don't like motherboards with built in wifi controllers. In principle, you could wirelessly 'tickle' a LAN adapter… although I would expect that to be rather novel - being able to both induce a suitable charge on the traces and read a response/simulate a connection remotely would be difficult to realize in practice. If you asked me to slap a device on a computer no one opens, I'd tell you it could be done. If you want me to do it from across the room…. maybe as a tech demo under controlled conditions to wow the impressionable. From a fucking balloon?… In principle, sure … if you have magic that can teleport a microwave signal to a specific region of space and control it with milimeter accuracy or otherwise account for that need via some self-coupling or correcting factor that someone found and kept in a binder.
If we were talking about old coax cctv or modems - yeah, we could hack the shit out of those remotely. If you have a device with any kind of wireless antenna on it - even without it being properly connected (such as a modern motherboard with the antennas disconnected), there is the possibility it can be convinced to function. Crowdsupply has some awesome open source projects for those who want to play in the radio and microwave realm (… probably a devgru/china lake hangout, as well - it's exactly the kind of stuff those guys do, just with a bit less access to have intel run off some custom projects on research fab nodes when necessary).
It could be as the chinese say - it's a weather balloon… I don't really see much this thing could do over a satellite, except it is below the ionosphere and would get better reception. It also went by a number of military installations - minuteman facilities, whiteman, scott, and stuff on the east coast. Even if it is honestly just a weather balloon - its course is intended to make us ask about it and stir up irritation.
I don't think it's so much about what the balloon was doing as much as it is about prompting a reaction by us.
The davos types have china selected as our successor, because they don't understand why economics makes the U.S. and Russia the world's exclusive superpowers - no other nation can hold the title, and the U.S. has warm water ports in spades.
However, what the proverbial they want is to avoid a war by having China replace the U.S.
There is not exactly a unanimous agreement on this, as the Chinese clearly have their own ideas and Russia has demonstrated the distinction between economics and finance such that the planned destruction of U.S. industry is now a mistake as Russia has been able to tell us "no" and we can't even declare a no-fly zone, much less enforce one or drive tanks through their cities.
The plus side of all of this is that we are seeing more domestic infrastructure spending… turns out you can't just buy more munitions, you have to actually make them (clearly, part of satan's plot to sabotage the righteous, the concept of matter is). The down side is that these are still gaylord faggots who are in coke-induced delerium surrounded by horse futas … so we'll have to retool the factories to build something other than things straight out of the nuclear code section of hentai.