Alan Turing, the man who broke the enigma code during WWII, is estimated to have shortened the war by over two years, and to have saved over 14 million lives. He was later charged for his homosexuality and was forced to undergo chemical castration.
Tragic but true - Alan Turing is widely considered to be the father of computer science. In WW II he decrypted German encoded messages. Winston Churchill said that Turing made the single biggest contribution to Allied victory in the war against Nazi Germany. After the war he was tried in court for being gay, found guilty, forced to take castration pills, and then driven to suicide. Britain has apologized. ~Via Pat Whitten
Joan Clarke Murray codebreaker at Bletchley Park during World War II, became deputy head of Hut 8 in 1944. Code breaking was almost exclusively done by men during the war. Clarke was paid less than the men and felt that she was prevented from progressing further because of her gender. She was a English cryptanalyst and numismatist. You have Joan and the women of Bletchley Park to thank for changing the History of the World AND the fact that you’re reading this on a computer!
In 2011, William Jones created an e-petition requesting the British Government pardon Alan Turing for his conviction of "gross-indecency" and the fact that he was forced to undergo so-called "organo-therapy" – chemical castration. This remains a shame on the UK government and UK history, after all he'd done for the nation. A pardon can go to some way to healing this damage. The petition has over 34,000 signatures.