I wouldn't say I necessarily agree with doing this when it comes to Facebook, but is there really no circumstance in which you think it'd be justified to cut off contact with a friend because of where they work?
For instance, if I had a friend whose job it was to design missiles that are used to bomb innocent people (Lockheed-Martin for instance) I would seriously reconsider my friendship with that person. Yes, it's "just their job" but choosing to have a job which requires having such warped ethics would make me reconsider whether I want to continue associating with them.
Nobody is forced to work at such companies. Yes, effectively all companies do things which we don't agree with on some level (unimaginably large amounts of tax avoidance being the most obvious example). But if a company's ethics are completely antithetical to your own, then I don't see how you could morally justify working for them.
(Obviously there are some understandable exceptions to the above -- the most obvious being that in the US employees are effectively blackmailed into working for their employer because they'll lose their heath insurance otherwise.)
On its face the statement is true. LM does design missiles, and some non-zero number of them have been used to kill innocent people.
I'm curious what part of the statement is important to you in making that decision though. Is it that LM is part of the military-industrial complex, full stop? That the weapons are used by the US military? That they are sold to and used by other governments? Would LM be acceptable if they created weapons that magically never harmed the innocent? What if they occasionally harmed the innocent but were always used by people with good intentions who were doing things you supported?
I was using Lockheed-Martin as an example of a "clearly immoral" company, you could replace it with any other example you can think of and the point would be the same (that at some point you have to accept that ignoring your morals in order to get a paycheck means you don't really have those morals).
As for my personal view, it's fairly clear that Lockheed-Martin props up (through lobbying) and profits (through government contracts) from the US war machine -- which in turn has killed millions of innocent civilians. And then there's the contractors that Lockheed-Martin has provided to government agencies to further strengthen the surveillance tools of the NSA, CIA, FBI, and so on. So, I think Lockheed-Martin was a good example of a "clearly immoral" company.
EDIT: You changed your comment after I responded to it. I don't think the ethics of hypothetical magic missiles is a super useful conversation to have (changes in technology don't change our underlying ethics, they just change what ethical questions are being asked).
On the question about unintended consequences, obviously in wars you can't guarantee zero civilian casualties and innocent bloodshed is inevitable (though still unjustifiable). But the US is currently engaged in several illegal wars of aggression (which is a crime under international law) and clearly planning to engage in several more. Personally, I think the "unintended consequences are inevitable in war" defense isn't available to you if the war itself was illegal from the outset.
For instance, if I had a friend whose job it was to design missiles that are used to bomb innocent people (Lockheed-Martin for instance) I would seriously reconsider my friendship with that person. Yes, it's "just their job" but choosing to have a job which requires having such warped ethics would make me reconsider whether I want to continue associating with them.
Nobody is forced to work at such companies. Yes, effectively all companies do things which we don't agree with on some level (unimaginably large amounts of tax avoidance being the most obvious example). But if a company's ethics are completely antithetical to your own, then I don't see how you could morally justify working for them.
(Obviously there are some understandable exceptions to the above -- the most obvious being that in the US employees are effectively blackmailed into working for their employer because they'll lose their heath insurance otherwise.)