Imagine that you've used a free, Web-based e-mail system for years, one that doesn't support the POP or IMAP protocols for downloading messages to a desktop client. Then, one day, you want to switch to a spiffy new webmail provider—how do you do it? Very, very slowly.

One obvious problem with Web services is that many make it difficult to leave and take one's data with you (the "data as hostage" business model). This is a special concern about companies like Google, which collects data in many ways and at such a rapid pace that it could conceivably lock up user data in a truly dizzying variety of ways: e-mail, blogs, search history, documents, spreadsheets, presentations, calendar, appointments, pictures, and even map route searches. Taken together, this provides an uncomfortably complete picture of a human life.

This sort of thing will still worry privacy advocates, but those concerned more with data portability should find a lot to like in Google's announcement today of its new Data Liberation Front. The Front is an in-house engineering team with a simple mission statement: "Users own the data they store in any of Google's products. Our team's goal is to give users greater control by making it easier for them to move data in and out."

The team works with all of Google's product managers to make sure that services from Gmail to Maps to Orkut to Analytics to YouTube all provide a "way out" when users decide to take their data to another service. As a site that makes most of its advertising money on the back of user-generated content (Web searches, e-mail, etc.), this seems like a smart long-term move—which is exactly Google's plan.

"We'd rather have loyal users who use Google products because they're innovative —not because they lock users in," said today's announcement. "You can think of this as a long-term strategy to retain loyal users, rather than the short-term strategy of making it hard for people to leave."

According to the new project website, the Data Liberation Front is "two-thirds of the way through" its work on Google's various services. The team has been around internally since 2007, but they're now going public with a branded website and name chosen to echo "The Judean Liberation Front" in Monty Python's Life of Brian.

The group uses open standards for data export, such as OPML for Google Reader and KML for Maps data, and isn't pushing for any new data formats. It's also not trying to launch a "consortium" publicly, though "we'd be thrilled if other companies followed our lead." For now, though, going public with the commitment to openness looks like savvy marketing; it shows a confidence in Google's products, and also offers a chance to remind users of the company's ostensible non-evil nature.