Why is Google blocking me?

Hi,

I am using a search engine scraper to get some urls to perform some analysis. The scraper works is a multi threaded application that retrieves many pages at the same time. It supports proxies. I downloaded and tested a huge list of proxies about 10000. So I started scraping data from Google when I found out that my real IP got banned.

It never happened before.

Is there a chance that some of those proxies are not really anonymous and are sending my real IP address to Google?

guess panda is always behind wether u sleep or awake it is always in a mood of screwing!

I think this is related to anonymity, regardless panda is there, if a proxy server is sending my real IP then it is screwing me.