Many countries have laws against reverse engineering programs. Whilst I think these laws are stupid I would prefer to just use the open source program than mess around with the closed source alternative.
According to Wikipedia[0], reverse engineering is generally legal in the US:
In the United States even if an artifact or process is protected by trade secrets, reverse-engineering the artifact or process is often lawful as long as it has been legitimately obtained.
Actually have another look at that before you break the law on this yourself.
As far as I can see that article says that reverse engineering is legal in the case that: (1) the EULA doesn't mention it (I've no idea what Whatsapp EULA says - do you?). (2) it is done for the purpose of interoperability. What is being proposed by the GP is in fact not interoperability but security testing.
As I said before I think that the laws on this are stupid. But why worry about this when there is a great FOSS program in the same space?
Yes but it has 350M people living in it, half the HN, Silicon Valley, and Moxie with his team. It's not honest to say the US is just another country among 200.
yep, in other words around 4% of the world's population live in the US and of course this pales in comparison to actually large nation states, like india or china.