I mean, a self contained LAN is still feasible. Data can be a transferred through an air-gapped method like flash drives, DVDs, blurays, etc. It would probably be largely fine for most things, just slower.

Of course, any long-distance communication method could be compromised. Cell towers would be a huge risk, radios could be unsafe, and even cameras could be a risk since they can see a long distance. The power grid could send signals in the minute voltage drops as things draw more power.

In short, we’re fucked and we can only pick the speed and intensity.