The Polish democratic opposition used to do this in the 80's, during the communist era. As far as I remember, their technique relied on balloons, they would att

The Polish democratic opposition used to do this in the 80's, during the communist era. As far as I remember, their technique relied on balloons, they would attach a homemade antenna and tape player to a balloon, set it on a timer and release the balloon into the air. Before the transmission started, they'd be long gone and the balloon would have drifted far from the original site, making the perpetrators much harder to track down. As a bonus, they'd get an antenna high up in the air (which is good for reception), which was also hard to disable, even if you managed to pinpoint its location.