I am planning to write a post soon responding to a very interesting debate between Jacob Imam and Trent Horn, but here’s a teaser.
In Trent Horn’s defense of 401Ks, he asks, “If we can use YouTube, why can’t we buy stock in Google?” In other words, what is morally different about cooperating with Google in the sense of doing business with them through the use of their service, and cooperating with them in the sense of purchasing ownership in the company itself?
It’s a great question, and my answer will hearken back to the Thomistic doctrine of double effect, which I discuss in previous posts, namely, that it is permissible to do an act that one foresees as having both good and evil consequences, if the good consequences outweigh the evil, and are caused with the same immediacy, as a separate byproduct, not as a result of the evil itself.

This principle explains the problem we feel with the logic of most movie villains (at least of those who offer an explanation for their insanity). They always want to correct some wrong in the world (like starvation due to overpopulation) by some wrong means (like killing half of the people in the universe). Why do we hate them? Because they are violating the fundamental moral principle that—even in the most desperate of situations—it’s always wrong to “do good that evil may come,” as St. Paul condemns in Romans 3:8. Why is it always wrong? Because we cause an end less directly than we cause the means to it. By doing evil that good may result, we lose faith in God to provide the means for us to wholly obey him. It’s failing the test of the Sacrifice of Isaac.
The difference between being a user of Google services and being an owner of Google is that the good that one achieves by being an owner is achieved by means of being an owner, as a further result of the ownership (and all the shared responsibility that entails), whereas in the case of being a user of Google services, one causes the good that they intend simultaneously and in causal parallel with the evil that they permit Google to do.
Ownership in Google is a means to that monetary end. (I am assuming one owns stock in Google because they want to make money.) I tolerate that I am an owner of Google and Google is thereby using my capital to do evil things, because by means of Google getting money, I may achieve whatever good I intend to do with my share. No matter how proportionately great the reason—providing for my kids and my elderly relatives, or what have you—the evil is still causally prior.
But when I use a Google service in such a way that Google gets money (from me or from advertisers by my passive complicity), I do not achieve whatever good I intend by means of Google getting money; if anything, I achieve it in spite of Google getting money, as is evidenced by the fact that I could achieve my purposes just as well, or even better, if I gave Google no money at all for their service: then I could browse more efficiently, or listen to music without those contemptible interruptions. Indeed, I would much prefer if their services were entirely free, of both fees and advertisements!