If this is BS, then that relieves me. This is what a trustworthy acquaintance who is an engineer at Facebook told me. As onedev said below, all access is logged and changes can be rolled back. Engineers use live user data for their local development and testing. But maybe this level of access is limited to certain feature teams.
That's what a Facebook employee told me last month.
For similar stories: Katherine Losse, Facebook employee #51, wrote a biography [1] that includes details about early days when the master password was "Chuck Norris". And this 2010 interview [2] with an "anonymous Facebook employee" (for what that's worth :) also describes how engineers can access user data.
I've been given root access to a handful of internal servers as an intern at some companies in the past, but never database servers or production, customer-facing servers. That seems rather ridiculous.
