Piper XXX: "Center, Piper XXX with you at 10,000. Request radar vector and ground speed check....."

Center "Piper XXX, turn left, heading 303, your ground speed reads 150 kts."

Piper XXX: "Turn left to 303, GS 150 kts."

Citation xxx: "Center, GS check please....."

Center: "Citation XXX, GS reads 360 kts"

SR-71 Blackbird: "Ah Center, Air Force XXX with you, request GS and altitude check...."

Center: "Air Force XXX, we show you doing 1540 kts at FL700"

several seconds of silence

Piper XXX: "damn, You win, Air Force"