Most people willingly ignored this because they feared that panic and a'bank run' on tether would cause a crash similar to Mt.Gox.
Tether is infact a fed instead of the fed, but without the largest military power in the world to defend it, a scam that is backed by nothing and there have been a lot of attempts to point that out. Check out 'bitfinexed' on twitter and medium.
You should look up "shadow profiles". Facebook knows almost everything about you from people you interact with by collecting that data into your shadow profile. Also, regardless of what you do, Facebook (along with other big tech companies, but Facebook in particular) is a menace for society and should be treated as such.
Let's say your wife is looking for a job, but you plan on having kids some time in the future. That data is collected by either facebook, whatsapp, your mobile phone provider or something else. Or her data collecting menstrual calendar isa sending back info (yes this actually exists).
Now, it's illegal to ask that in an inteview, but the boss might buy that data, and your wife will never get a job.
Let's say you are a supporter of a political movement that is not mainstream, all of that data can be used to exclude you from society one small step at a time.
>Like, why does such a critical system like MCAS take only a single AoA sensor as input
The classic approach is to have three sensors, so in case one fails you can know which one. Having two only indicates something is wrong but is not useful on the fly.
Mental health has become far too medicalised in the west in the interest of multiple large entities (including but not limited to the pharma mafia), so your vision of Japan might be influenced by your standards for mental health.
Worth pointing out is that the mental health issues are only the symptom and not the cause, the cause should be adressed first rather than the symptoms.
Why would you torture yourself like this? In mathematics understanding is everything, and using the time to listen carefully and understand is more important than having perfect notes, handwritten notes are quite enough.