First of all, it is not like FB employees are pushing people into gas chambers in Dachau, FB usage is not obligatory, what I keep telling everyone who complains about FB censorship or privacy abuse - I don't have FB account because of that.

In the same way we might ask to step out Coca Cola employees (say, delivery truck drivers), because drinking Coke is bad for ones health. Or HSBC employees because HSBC was laundering narco cartels money? Or John Deere employees because company forbids farmers to modify tractor software?

All of those practices are immoral and bad, but why chase the weakest, whose income, ability to pay rent, etc. depends on the employer? Why not target those, who are really responsible for that what is happening and who make huge money thanks to that?

I would say it makes much more sense to vote with our money, avoid services and products from companies we consider immoral.

Publicly discourage people from using such services and products, publicly stand against CEOs, shareholders of those companies, spread the knowledge about their personal responsibility for such kind of behavior - this is not that difficult and actually can make a difference. Imagine PR outcome of a conference that would invite Mark Zuckerberg, but no one else would want to attend it? Mark shows up on, say, TED, and all the people leave the room during his talk? In the media-driven World surely this would become "viral" and even Mark with all his money couldn't ignore that easily.