Hmm neural networks in JS...nice!
You can find it here: https://userscripts.org/scripts/show/38736
Tip: You must have Greasemonkey Firefox Addon in order to install the script.After that just visit a megaupload.com download page and the captcha will be filled in automatically and the Download button "pressed"(explanation for noobs).
Get it while it still works :oops:
LE: How it works - https://ejohn.org/blog/ocr-and-neural-nets-in-javascript/