Gmail - Google's new webmail service - launched a couple of weeks back as a "Hotmail killer". However there are still some serious privacy issues around their use of the email/search data. EFF has in interesting insight ... While the media has largely focused on the fact that Gmail will scan the contents of your email messages in order to target ads, the more serious problem from a privacy perspective is Google's ability to link your Gmail account information with your Google web searches. By linking your complete Google search history - tagged with your name and personal details - to your email records, Google can create a highly nuanced picture of you as a reader and as a person. Such pictures present irresistible targets for government investigators, civil lawsuit plaintiffs, and even identity thieves. A single attack or disclosure could release deeply sensitive details about your life to the world without your knowledge or consent. Below, we explain how personal information from your Gmail account can be linked to your Google searches, provide a technical "how-to" for (temporarily) keeping the two separate, and offer our recommendations for a longer-term solution to the problem. Although we focus here on Google, these recommendations apply to any business - Yahoo, Hotmail/MSN - that offers both search and email services and can link the two. Google uses cookies - bits of identifying data that automatically allow a website to "recognize" you - to link every Google search you conduct on the same computer and browser. This could be used to help Google to refine your search results or their display to match your preferences more closely. Even though Google keeps this search information stored on its servers, without your name and other personalized information it has no way explicitly to link searches to your other activities and correspondence on the Internet. The problem is that the Gmail service may change this. All of a sudden, Google can know exactly who you are every time you search the Internet using its service. And not only that, its databases know who is sending you email, to whom you respond, and even what you write about. With innumerable search results and up to 1 gigabyte of email messages per Gmail account at its disposal, Google could pull together an extremely detailed dossier on each of the millions of people who use its services every day. Such a vast assemblage of nuanced personal information could become a bigger privacy nightmare than government projects such as Total Information Awareness (TIA). As we note above, Google isn't the only threat. Yahoo and Hotmail, although they're not (yet) offering to archive a full gigabyte of your personal email messages, can also link your email account to your search history - and to your instant messaging as well. Amazon is getting in on the game, too, announcing this week its new "A9" search service, which will allow the company to correlate your book browsing and purchases with your search and click history via cookies. More here ...