Be careful what you tweet, because what you say online is never really gone. That's doubly true for public officials, whose deleted tweets are being preserved for all to see in a new online repository managed by the transparency-minded Sunlight Foundation.

The project, Politwoops, has recovered nearly 3,400 tweets that members of Congress, governors and other public officials have deleted. Most were innocuous misspellings or broken links, but some proved to be grounds for controversy: U.S. Rep. Jeff Miller (R-Fla.) deactivated his Twitter profile in May after tweeting out a poll questioning whether President Obama was born in the United States.

The account is still suspended, but, thanks to Politiwoops, the tweet remains.

“In politics, Twitter is part of the ever-present ‘spin room’ of the digital age. But unlike other mediums, the record of events can be edited,” said Tom Lee, director of the Sunlight Foundation. “Politiwoops provides a window into what politicians are thinking and how campaigns are honing their social media messaging.”

The Politwoops experiment demonstrates another wrinkle in the interplay between government and social media: How do social media and other electronic communications challenge the notion of an open and transparent public record?

According to the Reporters Committee for the Freedom of the Press, only three states (Florida, Illinois and Kentucky) have adopted guidance and statutes that specifically define official activity on social media accounts as part of the public record. However, the group's review of policies in all 50 states does note that, in a court of law, most states' existing open records law (which usually includes broad definitions, such as "electronic" or "computer-based" information) would likely cover social media.

"It's unsurprising that the rules are still evolving," Sunlight's Lee told Governing, "but I think the expectation is that this should be available to the public, that there should be a trail for watchdogs to follow."

A 2010 survey by the National Association of State Chief Information Officers found that records retention was one of the most commonly cited concerns among government officials about social media use. Some state bar associations, such as Florida's, have advised state and local agencies to err on the side of caution, and new social media archiving websites, including GovLive Vault and ArchiveSocial, have begun marketing toward government entities.

Many states and localities have taken a proactive approach. In a Governing survey of more than 350 government employees and officials, 55 percent said their department or organization was using a Facebook or Twitter account to serve a transparency-related function.

“Government — all organizations really — must communicate in the spaces where people are connecting, gathering information and forming opinions,” one participant said. “Today and into the future, those spaces are increasingly online social media.”

Some states are also using social media to their advantage: the Connecticut General Assembly solicited official testimony from Facebook and Twitter on the state’s response to Hurricane Irene and its aftermath.

A Facebook page created specifically for the issue garnered 68 comments, and all were entered into the public record along with those delivered in person at the Capitol. As State Senate President Donald Williams, who proposed the idea, explained: If 68 people had testified for three minutes in person, that would have amounted to seven hours of testimony.

"In this case, no one had to leave their home; no one had to miss work," Williams said in September. "The access to constituents was instantaneous. They were able to provide constructive ideas. I'm not sure this will work for every issue, but regarding issues of general concern, I think it can be an effective tool."