There are even cases where someone has, in fact, sent items to a national newsfeed inadvertently. The technology makes it just as easy to get the message to other countries as it does to other states. This often makes it hard to remember that you are often operating nationally or internationally. With non-computer communications it is usually clear that you are mailing to another state or country, but with computer newsfeeds you may not be able to tell without a lot of work. While it is not reasonable to most people that you should know the rules in every conceivable jurisdiction, it is equally unreasonable to assume that you don't need to know about any of them.
System administrators tend to get angry about things like chain letters on their system.
Whenever somebody in authority saw Mr. Blow's letter, they simply deleted it. They cause a flood of letters that interferes with normal usage of the system. We just delete them every time we see them. They are illegal anyway, and besides, they are being sent over MY system, using MY disks, and over network connections that I pay for. I have every right to keep this sort of stuff off of my system.