https://contribute.barackobama.com/donation/election-night-w...The extra information was present in the GET parameters being passed through the URL query string, if you look closely you will see this:
&amounts=|5000|5000|5000|5000|5000|5000|5000|5000
Removing this simply reverts it to it's normal state, however you can set the amount you want, some playing around revealed that it accepts only signed integers between 0 and 5000, anything over reverts to 5000, anything under reverts to 35 and is a string is used it reverts to the normal value.
