Ask HN: Worst examples of ambiguity ?

A recurring theme in industrial accidents and related issues is the ambiguity of 'English'. English not being a programming language it is very easy to make sentences that can mean different things dependent on the mindset of the reader.

Here is an example:

"When going around after an aborted landing: take off power"

During the landing of an airliner the captain decided to abort and go around, the key phrase, straight from the manual caused the co-pilot to reduce power on all four engines causing the airplane to stall and drop out of the sky.

English is full of opportunities for such mishaps, lots of jokes are based around them.

So, my question to you is do you have any examples of mishaps caused by ambiguity in English ?