I do understand where you're coming from, but personally, I think the issues are a bit more complicated.
On this occasion, it was an ill-timed joke that probably should never have been made. At the end of the day, any joke that can be construed as belittling to another persons faith is probably unnecessary and choosing what one says, and to whom, is a part of life that everyone should carefully consider.
That said, one would hope that an innocent joke made to a friend would not result in a death sentence. Sadly that isn't always the case in today's world.
Although I agree that "Even when you whisper something in a loved one's ear, it is no longer a secret", I cannot agree that communication made online should always be considered public.
For political dissidents, citizens living in oppressive regimes that need to express opinions - or ask for help in dire circumstances, journalists, lawyers, and many other people, communicating online privately is essential and does and can happen. Reliable VPNs do exist and they do allow people to gain digital privacy. Then there is Tor and for those people that want to go the extra mile VPN into Tor.
It is my strong opinion that people should be able to communicate privately via the internet when they want to, and reliable private messengers and VPN services are a massively important part of that process. However, one must use extreme caution and be aware of the limitations of these technologies. they must also educate themselves on how to properly use those technologies to ensure that they are properly evading snooping from those that they wish to keep their communications private.
One thing I disagree strongly with, and that makes me instantly think that the oppressors are winning the war, is that we should "only speak of things you want to be repeated." This I will never stand for.
In places where people can be killed for expressing unpropagandized opinions, and where those people are literally heroes for spreading truth, and/or attempting to overthrow unpopular authoritarian governments (whether they be local or nationwide power structures) - digital privacy and the ability to say what they want, without it being repeated to the authorities is of utmost important.
People shouldn't have to bite their tongue for fear that it will be repeated to the wrong people, which is why the anonymous movement has a lot to teach us in terms of how people can exist in the digital realm in a manner that allows them to spread their true inner thoughts without fear of repercussions.
RE: When VPNs and encrypted messengers can't protect you...