That must have taken a lot of valuable time. Which sucks because nobody else would bother to read it.
That is not the issue, the issue is that illegal information could be conveyed that way
Top secret stuff, terrorism ... would that turn the entire blockchain illegal?
It wouldn't turn the entire blockchain illegal.. but it would certainly put you on a watch list.
And I doubt terrorists would reveal their latest plans somewhere where anybody can read it.
An excellent point... to play devil's advocate though, they could send out a notice saying "go now" or something, signalling other jihadis to start an operation they planned earlier.
Which again would make no sense, because there are more convenient methods that don't involve leaving a gargantuan trace visible to all users of the internet.