It is serious business because it is a business hosting the chat. Business tends to be the most serious business of all.
This website is also hosted by a business. Also, given that the business was completely uninvolved in the case, I'm not quite sure why you'd even try to make this point in the first place.
In America you don't go to prison for being rude. That's completely ridiculous. If we send someone to prison for making stupid terroristic threats, that just means we have idiots in our justice system. It's not that big a deal, to be honest. But jailing someone for being rude is a bit orwellian, don't you think?
I'm still firmly convinced that the difference is entirely superficial. You can present either of these cases as "technically bad but not actually bad" - you've been focusing on portraying the Texas kid as "making stupid terroristic threats" (despite the fact that he did no such thing). Meanwhile, the British media focused on portraying the other cases as inciting racial hatred.
Both can sound serious at a glance (although I admit that the social effect of falsely calling someone a
trrrrrrist is probably greater than that of falsely claiming that someone's
inciting racial hatred, especially in post-Bush America), and both can be reasonably described as "being rude".