Actually. not combatants itself, but their PR departments and special provocators often have PRETTY active polemics over internet, this is part of any modern conflict.
Al-Qaeda and US very shit example, because they indeed not opposite sides in civil war, so neither side really connected with enemy society, so their chance to start any polemics - nill.
For civil wars its entirely another story, because its same peoples, who shit in same informational space. Not like their polemics really something other than NO U, but it do exist and in very big amounts. But yes, its doing PR departments, provocators and citizens itself, when PR department did work good and meme spread itself. Sometimes lowrank militants. High rank persons - almost never.