To the comment about whistleblowers vs. tattletales. In the US, whistleblowers in certain situations are entitled to a percentage of what is recovered. This is has resulted in tens of millions of dollars being paid out to whistleblowers so the motivations are not as cut and dry as @MotherOfDragons laid out.
I’m of the opinion that admissions offices appreciate whatever help they can get. Cheating on tests, ghostwritten applications, and falsified information by internationals (two countries in particular), are a huge problem for Adcoms. This is one reason, I suspect, that more Skype interviews are being done for internationals who are strongly being considered these days because not even TOEFL scores can be trusted coming from certain countries.