I wrote a script that retrieves stock data on google finance and prints it out, nice and simple. It always worked, but since this morning I only get a page that tells me that I'm probably an automated script instead of the stock data. Of course, being a script, I can't pass the captcha. What can I do?
well, you finally reached a quite challenging realm. decode the captcha.
there do exist OCR approaches to decode simple captcha into code. not seems to work for google captcha. 
I heard there are some companies provide manual captcha decoding services, you can try to use some. ^_^  LOL
ok, to be serious, if google don't want you to do it that way, then it is not easy to decode those captchas. After all, why google on finance data, there are a lot other providers, right? try to scrape those websites.
Google Finance recognizes my Python script as a bot and blocks it