A new Web code, HTML5, will send privacy activists into a frenzy and paranoiacs into a panic, because it allows marketers and advertisers to cull far more info about online users than ever before. Now in limited use, HTML5 will make viewing multimedia content easier, allow users to check email offline, and quickly find a business on a smartphone. Already, Internet shoppers are familiar with cookies, which allow easier tracking of stuff in online shopping carts, as well as logging on to websites without retyping a password. The new code will track far more information, storing much more data on users’ hard drives while they’re browsing. That means spying companies could track weeks or months of information, from location to blog text to emails to shopping carts. The World Wide Web Consortium, which oversees developers’ new code specifications, says it will hold a two-day conference about privacy.