All but a handful of EU countries. Lived in DK, ES and BG. I can tell you that very few teenagers speak English well enough to learn to program so they can start a Facebook at 18 year.

When I was a European teenager in the 1980s, I met many peers who were great programmers - given their age (around 15, 16). They all spoke English very badly. They just weren't interested in English, only in programming languages. These were self-taught kids who were also good in math and science. Apparently you don't need to know much English to get good at programming.

I think the argument was that a non-English Facebook likely wouldn't have taken off the way it has.

Have you been to France ?

No it is not except for Scandinavia and just around Denmark. In reality the further south you go the more you really need to speak the local.

I have found it a lot easier to get by (talking to locals) in Tokyo using English than in for instance Madrid.

I can't comment on Tokyo but just to offer another point anecdote, I've found it pretty easy to talk to people recently in Portugal, Spain, Germany and Belgium.

Most communication starts with my apologetic expression for the cultural faux pas which is about to commited.

I then move on to a token effort at mangling the local language which finally ends with me being asked to repeat in English by a patient native.

That's just not accurate at all.

It's even less accurate again if you're moving in business/tech circles and not travelling around as a tourist.

No, if you go as a tourist to tourist locations you have better chances. But as a local when you take care of daily things you'll need to speak the local, and that's a given. And really as far as recruiting talent between EU countries goes, the language barrier is real between countries that do not speak officially same language.