I stirred up some trouble with my previous post about Google search history. Since then I've gotten a lot of responses and had time to think things through a bit more.
I had forgotten that search history and personalization are not new products: both were introduced in 2005. That may explain why my friends and I were surprised to find histories; we probably turned it on and forgot about it. The thing that is new in the announcement that got my attention is that personalized search now uses the same login as your personalized homepage. Which means a lot more Google users will access it.
I don't think the search history product is evil. It can be useful and the straightforward opt-out seems responsible. But there are privacy issues (e.g.) and I don't like the confusing and less than transparent way history is enabled for users. And I'm still not positive, but I believe search history is enabled for new users without an explicit opt-in. If so, I think that's a mistake.
Privacy is a very difficult thing. Google tries in good faith to make responsible decisions for its users. I just disagree with some of those decisions, particularly when it's not entirely transparent how and when data is recorded. As a society we need more open discussion of privacy issues so we figure out where to make appropriate tradeoffs between functionality and privacy.