Working for Facebook is a morally bankrupt position. If you are an engineer you have plenty of job opportunities available to you and there is no excuse for you to continue contributing your labor and time to a wholly malignant organization. At a certain point one has to ask how we as an industry will start dealing with those who continue to take a paycheck from Facebook even in the face of constant and horrific evidence of wholesale ethical violations and negligence.
Your point? Should we stop working in IT and go back to the fields?
Also, I fear that HN somewhat forgets the world is not SF, in Europe going to work for Facebook/Google/Amazon is a enormous bump (we're speaking 2-4x) of salary for many people, which in some cases means you can buy an house after 3-4 years even with the crazy rents back in your home country - and that's HUGE. Why should those people spend their time slaving as a subcontractor for yet another TLC/bank trying to squeeze their customers dry at the first occasion while getting 25% the salary and zero benefits? Are those less evil?
What needs to happen is that people keep applying pressure so facebook is forced to adapt its business model even if it hits their bottom line - which is already happening apparently.
You should change this.
I'm pretty sure you can do good even within facebook, doing your utmost to keep the company accountable (from my experience in another big corp, we don't see 1% of what's happening inside it, and how many people are facepalming - and we'll never know if many things were just humans being stupid or actual calculated decisions). You can also keep your guard up from outside and force facebook to fix itself (obviously, as much as its business allows) from outside, for example pushing it to hire more moderators and get as better so to prevent things like myanmar from happening again.
What I'm saying is that it's impossible (and in my opinion, pointless) to claim moral superiority and to accuse people of being morally bankrupt because they work for corp X.
There are plenty of companies which can't easily be categorized as having significant negative effects to the world. You can work for a "bad" company but consciously constrain your work to a business unit which improves customers' lives.
What you're using is false equivalence. You know what the worst thing for the environment is? Being born. Why do people insist on living when everything is bad? Reject the notion that you're powerless to change things.