lucy24 - 12:27 am on Dec 19, 2012 (gmt 0)
My reaction was to the astonishment, not to the existence of the button.
There's a difference between "do not click here" on a web page and a big red Emergency Override button in some physical installation. Although even those may be accompanied by "break glass ..." with further instructions.* If they don't want people to click, what's the button doing on the site? Seems perilously close to Attractive Nuisance. (Your jurisdiction may have a different term.)
If we met something of the kind on a real www site we would probably head straight for View Source and see what's up. But that's us :)
* This is speaking as someone whose four-year-old once saw a bright red handle clearly labeled PULL.