1960s USSR. The peak of KGB paranoia. Neighbors are ratting out neighbors. Employees report their coworkers to the KGB for innocuous jokes. Nighttime knocks on the door are commonplace. Regular citizens are labeled enemies of the people and taken away. A group of university students are on a government-sponsored trip to a conference, 6 of them sharing a hotel room, as was commonplace on such trips. None of them know each other. At night, they talk merrily amongst themselves, laughing and enjoying themselves until one of them starts sharing political jokes. They share a nervous look, but one of them confidently says, "Come on, we are obscure students attending a random science conference in a far flung region. How can the KGB possibly care about us? Let's carry on!" At that point, another one of them hatches a brilliant scheme. Under the pretext of using the bathroom, he saunters down to reception and requests that at precisely 9 PM, they be brought six cups of tea. He goes back up. He sits pensively for 10 minutes, and at 8:59 he says: "Hey, guys, I wouldn't be so sure we aren't being listened to. Here, I'll prove to you that we're being overheard." Looking up at the sky, he says: "Mr. KGB Sergeant, would you bring us six cups of tea, please?" At that point the door opens and six cups of tea are brought in. Everyone stares in shock and horror, staying quiet for a few minutes. At that point, the jokester sneaks out and walks down to Reception. "Thank you so much for bringing the tea at 9," he says, "you helped me pull the funniest prank on my fellow students." "You are very welcome," responds the woman at reception. "And yes, it was indeed a funny prank. Our sergeant also liked it!"