It's almost like Googling someone: Log on to Facebook. Join the Washington, D.C., network. Search the Web site for your favorite school system. And then watch the public profiles of 20-something teachers unfurl like gift wrap on the screen, revealing a sense of humor that can be overtly sarcastic or unintentionally unprofessional -- or both.
Unless an employee's online activities involve the employer, a hands off policy is the most prudent course of action. If an employer has a policy of firing workers for online activity, then it could be argued that they are liable for the online activity for those they did not fire. An employer with a hands off policy for off-site activities is in a strong position to deny any liability.
In a free society employers do not have the right to limit an employee's speach. If this changes we would no longer be a free society. That would be a shame, a real shame.
note - as to the gender attitudes contained in the article, well, it is no mystery why The Washington Post has difficulty attracting female readers.