This Kitsap Sun article discusses the thorny Public Records Act and retention issues when government agencies use social networking sites like Facebook.
Here's the deal: Government is different than private people and businesses. Government is not a teenager on Facebook, or a business using Twitter to generate business. Government can tax and imprison; teenagers and businesses cannot. Government is subject to laws that allow the boss--the People--to know what's going on. Comparing government to private entities is not useful when it comes to transparency. To see what the government is doing, all you need is a public records request. To see what a private person is doing, you need a search warrant and probable cause. Quite a difference. Thank goodness.