I think there are more than a few countries where this sort of thing could easily happen. Tech talks get canceled at the behest of the powers that be with some regularity, I don't think requests to take down source code would be out of the question.
You think that, but your links are to two cancelled presentations at conferences, neither of which has any clear connection with the 'powers that be', unless you consider the SEI and Carnegie Mellon University to be the 'powers that be'.
Both those conferences occur in a single country, one which was not even able, under its own laws, to effectively suppress the distribution of cryptographic code when it was legally considered to be militarizable as a weapon.
https://www.washingtonpost.com/blogs/the-switch/wp/2014/07/2...
http://www.csoonline.com/article/2947377/network-security/pr...