As I understand it, this Bank of America/Merrill Lynch assessment of Bitcoin was leaked. "BTC surpasses Western Union in market capitalization", and much more.
“As a rough analogy, suppose competing journalists (miners) are asked to
document the national news on each given day for the National Archives1. The journalist is asked to write down the events (transactions) in a book (block) and the Archive will eventually buy one such book for a fixed fee. To determine which of the books the Archive will buy the archive has an additional requirement for journalists that the book contains the fingerprints of 10 people whose birthday was on that particular day. Note that the list of people isn’t related to the national news (transactions) but is simply meant to control the supply of books coming out per day. As more journalists collaborate to find people, the Archive increases
the number of fingerprints required.”