Angry Birds for Chrome already hacked (thenextweb.com)

This would more accurately be described as a "cheat", rather than a "hack".

Its not a surprise. Their js is obfuscated to hell and back, but there's nothing to prevent someone with the patience to completely get a clean copy of the source of this version of the game

hack comment used:

"hack", interesting use of the word

angry birds uses local storage to remember which level you last beat. you can modify your local storage. move along.

C:\WINDOWS\winmine.ini