Such people are barely known by the public because those who are asked for bribes never reveal these things to the public because they know the ones asking for money are in power and if they come to know about what they did, they might never allow them to get into the position ever.
You are right, mate, it's not just tied to one country, and for those countries where such news is not heard, there's no assurance that such corruption is not going on there. The truth is that some of those things are done secretly, so no one will disclose them, and even if you disclose the information to some people, they will not believe you because they can think that you are only trying to paint the organisation black. Also, when one is in this kind of situation, one has no other option but to pay and move on to the next stage. There's one celebrity whose autobiography I read, and she said she was only acting in some movies that did not put her name in the public eye, but that during the shooting of one interesting movie, she had to pay for the role she chose to play in that movie, and from there, she started receiving requests to be featured in some movies.