There is no whistle to blow. It is fairly well known that all international calls into or out of each country are monitored by bots using speech recognition by the related agency for each repsective country. This has been the case for a very long time. Before bots, there were listening stations with thousands of people monitoring calls. There would be nothing for Snowden to leak in that regard. The only place this has been taboo is when the NSA is doing it within the country. They too use bots, as there is no way you could hire enough people to listen to the calls. Only flagged calls are listened to by people.