While the world is still trying to figure out how much the NSA is spying on them, this MIT website offers a glimpse at the personal data email users reveal online every day

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Metadata is a word that was once reserved for the halls of high-tech companies and academia. But since the revelation of mass surveillance programs by the National Security Agency (NSA) — which collect troves of big-picture data on American citizens — the concept of data about data has entered the public lexicon. Now, the techies over at MIT’s Media Lab are giving us a glimpse at our own metadata, giving us a cold, hard look at the bread crumbs of personal data we freely scatter across the Web.

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Immersion, which launched on June 30 after years in development, asks participants for access to their Gmail accounts, and in exchange, it creates a visual map of their networks. Each “collaborator” — or person with whom the participant has exchanged at least three e-mails — is represented by a circle, which is then connected to all the other circles in one big web of relationships. Professor César Hidalgo, who spearheaded the project, told TIME that the result is a piece of very personal art. “It’s a picture you’ve been painting not with pigments and brushes, but every time you send an e-mail or get in touch with someone,” he says.

The program received such heavy Web traffic — more than 43,900 views between Monday and Tuesday alone — that the site temporarily broke. Hidalgo and his team are working to equip the program to handle the thousands of requests for metadata mapping, and currently, interested participants must add their name to a queue.

Much like the government phone-surveillance programs, Immersion doesn’t need to access the content of communications. Instead, by gathering information about the senders and recipients of all the e-mails in an inbox, it can create a detailed portrait of the user’s social connections. Each person’s picture on Immersion is as unique as a fingerprint, but much more informative.

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In this case, metadata isn’t just about numbers and grids: it’s personal. “Immersion shows you the data that you already share with others,” says Hidalgo. “You log into your e-mail every day, but just by taking a small fraction of your e-mail data and presenting it in a different way, we’re showing how much information people can learn about you from this data.”

The MIT Media Lab team began working on the project long before the NSA surveillance leaks, so Immersion is not an overt commentary on the NSA. However, it is a commentary on privacy — and how little of it we have when companies like Google collect mountains of our metadata. While reports have surfaced that the government has direct access to servers for Google, Facebook, Yahoo and other online companies, the Internet giants have vehemently denied knowledge of the program.

There are many differences between a site like Immersion where people share information voluntarily and government-run programs, but a key one has been especially warmly received; Immersion allows participants to permanently delete their information from the database. And in the world of metadata, that’s a pretty revolutionary idea.

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