...flying controls, linked by levers as on some learner cars, the regulations prohibit more than one person using the controls atany one time. This is to prevent a conflict of intentions working their way through to sensitive flying controls. But as...
http://www.computerweekly.com/DowntimePDF/pdf/rafjust.pdf
...end of the link was located. On arriving there and brushing past the sign that said "PLEASE DO NOT CLOSE THE SHUTTER ATANY TIME" they found that the internally-located laser transmitter/receiver was no longer pointing through a glass window...
http://www.computerweekly.com/blogs/it-networks-and-communications-blog