In an extreme case of “be careful what private information you post on Facebook,” Bradley Manning’s profile on the social network is playing a key role in the WikiLeaks investigation and offering devastating insight into the army private’s mindset during the period preceding his alleged leaking of documents-the largest intelligence breach in U.S. history.

Equally interesting is how Facebook has become the platform for those on all sides of the Manning debate to share their views.

The PBS program “Frontline” obtained the full archive of Manning’s Facebook page for their piece on the investigation, “Wikisecrets,” running tonight. Manning’s increasing unhappiness with “don’t ask, don’t tell,” support of California’s Proposition 8 and frustration in his personal life are subjects openly shared on Facebook, along with his likes of various lesbian, gay, bisexual and transgendered groups.

Gay rights groups and publications like The Advocate are closely tracking Manning’s treatment and story. There’s even a Facebook page called “Queers in Solidarity for Bradley Manning.”

And Facebook is the major platform for both pro- and anti-Manning voices to express themselves.

This page asks whether Manning should be tried for treason. Another is titled “Bring Home Bradley Manning.” Then there’s the “Bradley Manning Support Network.” And the “Save Bradley” page boasts more than 10,000 supporters.

How do you think Manning’s own Facebook page will influence the outcome of the WikiLeaks investigation?

Photo courtesy of Associated Press.