Poisoning dissidents is not biological or chemical warfare. For context, US dropped disease ridden insects and fowl feathers during their war on Korea. Am example of chemical warfare is their use of Agent Orange in Vietnam to hurt their agriculture which has ended up poisoning their water supply to this day.
No one is asking you to trust Russia. But Russia doesn’t have 300+ labs over the world inventing novel ways to kill for them.
Even bigger issue is the fact that US routinely engages in chemical and biological warfare on top of being the only country that has used nuclear weapons not only in Japan (twice), but also in Iraq in the form of depleted uranium rounds.
If there is one country in the world that cannot be trusted to have these kinds of facilities it’s the US. I really hope this chicanery comes to an end before something horrible comes out of these labs.
Where does the file go if it is named with a.txt?
This technique is usually used with checksums because they have a predefined length and alphabetic characters can be safely casted to lower case. How do you want to differentiate between upper case and lower case here asauming that you are using a file system that is sensitive to it?