It's a web faux-pas, the equivalent of having your whole site in Flash, or trying to disable right-click for fear that someone might steal your precious, precious content.
It's not yours. He can do what he wants with it.
Unfortunately, cramming spam into copied text seems to be getting more popular, and rudeness aside it's a potential security risk (i.e. if an unsuspecting help-seeker copy-pastes a command line and it turns into a completely different command line in the buffer). Is there a plugin yet to disable copy-buffer spam specifically, or would I need to disable JavaScript completely?
I copied it with the intent of putting quotes around it and adding the link to the end of it. However as is, i had to copy it into an editor and mangle it there, before posting it in chat.
That doesn't mean that it isn't very disrespectful behavior to his audience. :)
Only because one can do something doesn't mean one should.
Anyway, that blog is hosted on a 3rd party service, owned by an ad company. It's not that easy to blame him for what the service does. (Does Mish even know that blogger inserts ads there?)
http://i.po.st/share/script/post-widget.js
I've also never seen that on another blogspot blog, so while they might've added more stuff, i don't think it's that.