It is interesting. There are several factors at play. The chances of a random review on FB showing up are much lower than a background check when applying for a job. The "returning citizen" community is large in the US and while not a "tight" community, it is tight in the sense that they do talk and recommend companies that positively help them. Many also have a feeling of being wronged by the "system" and when someone takes advantage of them they have no problem letting them know.