The US government holds that Bitcoin is property not legal tender.
Legal tender has a very specific and limited meaning relating to payment of debts - if you owe a debt, then an offer of legal tender to settle it cannot be refused. Not being legal tender is not a barrier to something being used in commerce, even by the government. If both parties agree, they can use whatever payment system they want (as long as the IRS is kept happy by declaring a US$ equivalent where required).
"Go to bed NOW or you don't get to go to your friend's house tomorrow" is very obviously exclusive to an adult -- but to a kid, they figure they' ve got options.
I'd say the opposite. The kid is thinking if I go to my bed now, I am definitely going to my friends house, and I can get straight out of bed again, because once I've fulfilled the request the outcome is decided and the threat of not going to my friend's house cannot be pulled out again for another situation. It's the adult that figures the options they are giving are not exclusive, and may very well decide the child is not going to their friend's house even though they went to bed NOW as requested.
I'm pretty sure most font systems already DO do this.
Usually not the font systems themselves, as the font system API needs to be designed to let you use fonts in the way that suits your application, and not have random substitutions happen behind your back (though the font system provides the API functions to figure out what a good substitution font will be). But higher level UI libraries, like GTK, Qt, MFC, Windows Forms,Core Text, Skia etc will do it.
one can almost always treat utf8 as a byte stream. except in the rare case where one needs to know where character boundaries are.
UTF-8 is designed to be treated as a byte stream - even when detecting character boundaries. If a byte is >0x7F and <0xC0, then it is not a character boundary. If you want to be really strict, filter out the invalid bytes (0xC0, 0xC1, >0xF4), then everything else is a character boundary.
Even before this attack, there wasn't a single mainstream publication in the U.S. or Europe that would dare publish any depiction of Mohammad, or probably even any criticism of him. These terrorists were just eliminating one of the few remaining forums that was still willing to take on Islam.
Drawing depictions of Mohammad is not "taking on Islam". It is trolling. There is no purpose to it other than baiting the nutjobs that would murder your whole office for the offense you cause them.
Thus spake the master programmer: "After three days without programming, life becomes meaningless." -- Geoffrey James, "The Tao of Programming"