Edit: I've had a chance to think about it after a cup of coffee and I take back my comment. Everyone deserves a second chance. Everyone gets the same ethical review.
Edit: I've had a chance to think about it after a cup of coffee and I take back my comment. Everyone deserves a second chance. Everyone gets the same ethical review.
Why wouldn't a future employer take that into account?
I might add that prior employment at Facebook is very positively correlated with engineering talent -- you are not just selecting against something orthogonal to engineering talent, you are actually selecting against something that indicates they are a good engineer, meaning you have a smaller labor force you are willing to hire and a lower quality one. Go tell HR and your boss that you have prejudices against people from Facebook and you are going to discriminate against them in hiring as a consequence, see how well that goes for you.
The first part is true. The second is a leap, plenty of high quality talent actively chooses to not work at FB, or happens to not work there. By not selecting from the former FB pool I have not lowered the overall quality of my labor pool. I have increased the integrity standards though.
len(set(high quality talent) - set(ever employed at facebook)) < len(set(high quality talent) - set(refuses to work at facebook))
Note that "refuses to work at facebook" doesn't select for engineering talent, while "ever employed at facebook" explicitly does, meaning the average talent in the set containing facebook employees is higher.
Given all this, you have to fill the roll (or why hire?) and you don't have infinite time (there is a cost associated with every day you've not filled the role relative to it being filled). Given those constraints, if you limit your pool due to prejudice the optimal outcome is for you to hire a lower quality person versus the situation if you were not prejudiced; if you hire the same quality person, it means you likely paid for it in another form, namely the cost associated with the role being unfilled longer.