But one user, a paramedic from Connecticut, unexpectedly found herself at the center of what may turn out to have been a precedent-setting legal battle -- by writing about her job - specifically - criticizing her boss.
Dawnmarie Soouza wrote, "Love how the company allows a 17 to be a supervisor." 17 is code for a psychiatric patient. And after colleagues joined in the discussion, Souza twice referred to her supervisor in more derogatory terms.
That led to her being terminated, and her lawsuit, the settlement of which one law professor tells CBS News "really has expanded the free speech rights of American workers//If they are communicating about the workplace, and they're talking about their supervisors, then it's a protected activity."
"Early Sow" co-anchor Erica Hill interviewed Souza and told her story: