During the cold war there were several western broadcasters that were funded to broadcast on the territory of the Soviet Union (see [1]) . This had a big influence on the country's people's minds. Everyone was able to listen to the point of view of opposition using a simple standard radio receiver.
Nowdays WiMAX-type networks may be deployed to countries like North Korea, Iran or Egypt (and other oppressive countries) with similar technologies. Laptops or simple cellphones that are already widespread in the country may be used to access the network. People can start criticizing their government and coordinate their efforts for change.
Just a general thought that doesn't lead anywhere. But I thought it is worth it to publish it somewhere.
[1] http://en.wikipedia.org/wiki/Radio_Free_Europe/Radio_Liberty#Radio_Free_Europe
Radio receivers are passive devices. They do emit a small amount of RF, but it's limited and easily shielded. Worst case, you can build a completely passive receiver like a crystal radio. (NB for the EE pedantics: yes, I know I'm simplifying. I don't mean passive vs. active as in component definitions; I mean intentional vs unintentional radiators)
WiFi and other networking technologies are active transmitters and are quite easily detected. The same tech that's used to sniff out unsecured hotspots can be used to detect "dissidents connected to the internet."