The tech companies you work for do often engage in illegal activities, and some of your collegues are complicit. I'm sure it is an uncomfortable thought for some of you, but this is all part of the public record.
This is certainly true in a lot of finance.
The sad reality is people are very predictable, even with basic data.
I can imagine the same thing done for text. The text might be encrypted, but interest keywords might be generated on-device and sent out-of-band.
I'm not claiming this is real, but I agree with GP.
For an example from non-FAANG companies, see illegal dumping of toxic waste by chemical companies, such as DuPont and PFOAs [1]. Despite knowing what they did was illegal, the math works out -- products with PFOAs were something like $1 billion in annual profit, and even when they got caught the fines and legals were a fraction of that, spread out over many years.
So I personally believe these companies 100% would do shady shit if it increases their profit margins. And why wouldn't they? There is no room for morals in capitalism, and the drawbacks are slim.
[1]https://www.nytimes.com/2016/01/10/magazine/the-lawyer-who-b...
Despite the shady image they have, these companies go to great lengths to avoid doing shady things (because ultimately it’s bad for business). Not to mention the hundreds of tech employees that would have to be involved and keep quiet in this type of “conspiracy”. It’s incredibly unlikely, I truly believe that.