When I stopped believing in Google's fundamental good nature
Once upon a time I might have believed in Google's fundamental goodness and well intentioned nature (probably with qualifications). Google themselves eventually taught me better, perhaps later than it took for other people to realize that they were an amoral corporation. For me, the moment of realization, the point where I knew for sure that Google's "don't be evil" slogan was inoperative, was the great Google+ 'nymwars', where Google (for Google+) declared that everyone on Google+ must use their real name and then attempted to enforce that (it went wrong pretty fast).
There were a large number of problems with Google+'s 'real name' policies. It didn't match how actual users referred to each other and were known online, including for people who actually worked at Google. Forcing people to reveal their real name does real harm and has real risks (something appreciated even back then in 2011, but which is more pointed today). And in practice, a 'real name' policy is actually a 'it looks like a real name to underpaid support people or some automated system' policy, where 'John Smith' is far more likely to be accepted than a non-Western name or an unusual one, even if one is not your real name and the other is.
Google knew all of this. People, including internal people, pointed this out to them at great length. A decent number of technical people who worked at Google protested. There were demonstrated problems with the actual enforcement and actions involved. And Google, in both their senior leadership and their ongoing policies, simply didn't care. All of the harms and the wrongs did not matter to them. They were going to do evil because they could, and because they thought it served their corporate goals for Google+.
(We all know how that one went; Google+ died, for all that it had some good ideas.)
Watching all of this happen, watching all of the protesting and good arguments and everything go exactly nowhere, is when I knew that my image of Google was wrong (and gone). Now I extend no more trust to Google than I think supported by their corporate and commercial interests. Google employees may care about "don't be evil" and doing the right thing and so on, but Google as a whole does not, and the employees do what Google tells them to.
(This elaborates something I said in an aside long ago, in an entry about why my smartphone is an iPhone.)