Friendly Bears joke
On a military training exercise, the British divisional command radio operators were getting very bored one quiet night, when breaking the silence a voice asked over the air, "Are there any friendly bears listening?"
After a moment, another voice replied, "Yes, I'm a friendly bear," and then another voice, "I'm a friendly bear too!"
At this point, the Officer at Headquarters grabbed his microphone and let loose a blistering tirade at the operators for fooling around on a radio link.
When he had finished, there was silence for about ten seconds. Then a small voice said, "You're not a very friendly bear, are you?"