Bing has formally responded to Google’s charges that Bing is copying search results, accusing Google of trying a “spy-novelesque stunt” and defending the use of customer activity to influence Bing’s search results.

Harry Shum, Corporate VP at Bing, is speaking right now at the Bing/Big Think “Future of Search” event (see Danny Sullivan’s live coverage here), and his comments are echoed in a new blog post just published on Bing’s search blog.

We use over 1,000 different signals and features in our ranking algorithm. A small piece of that is clickstream data we get from some of our customers, who opt-in to sharing anonymous data as they navigate the web in order to help us improve the experience for all users. To be clear, we learn from all of our customers. What we saw in today’s story was a spy-novelesque stunt to generate extreme outliers in tail query ranking. It was a creative tactic by a competitor, and we’ll take it as a back-handed compliment. But it doesn’t accurately portray how we use opt-in customer data as one of many inputs to help improve our user experience.

In his comments today at the “Future of Search” event, Shum went a little further, saying

It’s not like we actually copy anything. It’s really about, we learn from the customers — who actually willingly opt-in to share their data with us. Just like Google does. Just like other search engines do. It’s where we actually learn from the customers, from what kind of queries they type — we have query logs — what kind of clicks they do. And let’s not forget that the reason search worked, the reason web worked, is really about collective intelligence.

Shum added later: “We have been very clear. We use the customer data to help improve the search experience.” And in the blog post, Shum suggests all search engines are, and should be, doing the same: “We all learn from our collective customers, and we all should.”