I was working with in-office with a client when they came running into my work area. 

Client: Help! My computer is being hijacked! Someone logged in somehow while I was working and took over the keyboard. They are typing code into the spreadsheet as I speak. 

We rush over to his desk, where the same character is rapidly filling the spreadsheet. 

Me: Well, here’s your problem. 

I lifted the book weighing on the corner of the keyboard. The hijacking suddenly stopped.