Over the summer, I lived in a building that had a proximity card reader (RFID) that you had to "beep" into to use the elevator. I took the elevator to get my bike back upstairs after rides. I guess the RFID reader interfered with my computer, because one day I happened to glance down at it, and it read me as going 84.9 mph! I no longer have it stored in there, because it decided it wanted to die during my ride the week before last, and in doing so, it ate all my numbers.