It's an odd phrase, and I had to go spend an hour reading over the science (a loose term) of counter-speech.
No one says much over when it was developed. It could have been two thousand years ago and simply recognized as a 'gifted-argument'. It could have been developed a decade and used for chat forums that have popped up and seem popular today.
Counter-speech is where you encounter a negative or racist idea/dialog, and you counter it with good sense, sound debate, and being unwilling to accept the negative position. It is a tactic....more or less....that people are told to use in opposing a position. Once you establish a strength over this negative topic....you are the owner of the discussion (at least that's what the counter-speech enthusiasts note in their comments.
Twenty years ago.....arguments would have been limited to university campuses, political situations, bars, and newspaper editions. Today, with Facebook, Twitter, and a thousand-odd forums....anyone can spend time on an interesting topic...read the basic arguments, and reach a conclusion. In essence, people of today....have a heavier opinion status than their fathers had.
If some discussion started up on your porch, balcony, or at the local pub where you sit on Thursdays....today, you have around six to ten basic 'bullet-points' that you took from some chat forum or news page, and you argue from those points. Your interested parties may have just as many bullet-points and normally....this discussion would just come to an eventual end.....where people would part.
Free society has formed the simple idea of respect for opinion. People could think something....whether right or wrong....and society could live with that unwritten rule.
With counter-speech....the opposing side believes there is an all-ending point, and that you can only come to the end and believe that their position is right, period, end of story. The belief in this one side-fits-all....would normally bring some intellectural people to stand and just start laughing. Typically, debate is a healthy thing. At some point, debate could shift people to think that the winning point....is the only point. Weeks or months later....something occurs, and then they realize how bogus that winning point was, and trust turns negative.
Another issue with the counter-speech game-plan is that discussions will go into a heated area....with the potential for SEDITION to be tossed around when people get frustrated and start to use threatening verbal argument. Sedition? That's when you suggest subversion to the Basic Law or the Constitution. Simply saying you will vote against some action is not sedition. Saying you will oppose this law or this change to the law....well, that's sedition. You can get dragged off to some judge and be asked to cooperate or face jail-time.
Why this counter-speech thing gets dragged up now? Well....the state-run network....ARD....brought it up and explained the basic idea to Germans to confront the xenophobia crowd....those who dislike refugees.
Would counter-speech have worked against the Nazis in 1932? No. Germans held an election allowing the Nazis into a minor position within the Bundestag. Oddly, because you need a combination of parties to win a majority....to control the government....the Nazis ended up as the minor party and a partner. There never was a need for counter-speech. Even when you get to the mid-1930s and can see problems developing....where exactly and on what forum....would you have argued against the Nazi apparatus?
If you look across various state-run TV chat forums today.....counter-speech is alive and well. If an opposing view is required for a chat.....you arrange the panel to be one-defender, one journalist, and three-opposing view members. It'll seem fair with the moderator in the beginning, and about half-way through the panel discussion.....you realize that it's basically a four-to-one forum. By the end, you can guess that most viewers have bought off on the position sold to them. Right or wrong? It doesn't matter.
You could eventually take counter-speech and use it for global warming, higher taxes on the wealthy, increased social benefits, speed limits on the autobahn, supporting Greek loans, talking anti-capitalist ideas, and even arguing privacy positions over the internet. The one-opinion-for-all-fit.....if it doesn't truly fit.....you make it fit, even if it is a bit tight and snug.
Eventually, somewhere down the road.....someone will develop the counter-counter-speech idea. And we will all sit there and be dazzled/dazed by the technique.