Welcome to another edition of The DarkThreads Trivia Game! The first person* to send the correct answer to firstname.lastname@example.org wins! You must send the answer in an email, along with your name and shipping address. PLEASE, do not post your answer here!
*Only one answer per person/per email. If you won last time, you are disqualified from winning again this time. Associates of Mindgame Productions and DarkThreads are also ineligible. Sry guyz.
Now let's take a look at this week's prize:
Tru-Spec Men's Polo Shirt - in heather grey, sizes M - 2XL. These polo shirts are super-comfortable and made to last.
Here is your question:
What was the method that John Walker used to pass classified information to the Soviets?