A major problem for ITV companies in the United Kingdom has always been the geographic overlaps between regions. No broadcaster has ever chosen to fight for an audience if the opportunity exists not to.
On the continent, this situation has been broadly replicated, but with extreme political consequences. While an overlap between, say, French- and German-language transmissions may not be a problem thanks to mutual unintelligibility, an overlap between the broadcasters of two countries with a common language can be a problem.
Hitler's Germany used this unavoidable' overlap between Goebels' and Austrian state broadcasts to disseminate black propaganda prior to the 1937 Anchluss, weakening the position of the Austrian chancellor.
When WW2 ended in 1945, it left communist and capitalist systems eyeball-to-eyeball in the centre of Europe and no more so than in what remained of Hitler's fortunately short-lived thousand-year' Reich.
With Germany divided geographically, politically and militarily, both governments in the country were left with a problem broad swathes of western Germany and almost the entire eastern zone could receive each other's radio and VHF television output.
For most west Germans and the Federal Republic's government, this was not a real problem. While ARD and later ZDF picked up a reputation for quality television (by mainland European standards), the Democratic Republic's television service was, to try to be fair, awful at all times. Western viewers would rarely tune in for anything other than a laugh and were certainly never propagandised by it.
However, the situation was rather different in the east. While the west, as an open society, made few moves against communist broadcasting, the rulers in the east were not so forgiving.
Geography prevented the number one choice jamming the signal. The need for the largely isolated GDR to live up to its laughable middle initial also made it diplomatically impossible to jam ARD's transmissions.
So the Orwellian Ministry of Information in East Berlin chose a different tack.
West German television didn't openly aim propaganda at the east. But its existence itself was a challenge providing easterners with unbiased and accurate news, capitalist' entertainment and a forward-looking world view that the Politburo did not share.
Unable to prevent the population from watching, they created Der schwartz Kanal, The Black Channel', a peak-time news' programme where government (or Stasi) approved journalists provided a commentary over re-broadcast ARD and ZDF programmes.
In these bizarre, not to say downright creepy, programmes, West German broadcasts were pulled to pieces, with the presenter explaining to the audience the real' meaning behind the broadcasts they knew the population had been secretly watching.
News was freely re-interpreted. Drama was shown as nothing but arch propaganda against East German democracy'. The lives of westerners were shown to be empty, lacking fulfilment and above all cold to the concerns of each other except where money was involved.
The Stasi the secret police kept files on more than a third of the population. Building its profiles from informers, the Stasi requested that East German schoolteachers ask children to draw what clock they saw on television the night before.
Almost invariably it was that of ARD. And that, in the strange world that was communism, was reason enough to keep the Black Channel open.