What's the official explanation for the 'jannesp' incident?

CONTEXT: Multiple users logged in as 'jannesp'

Since that thread is now locked. I'm starting this new thread to ask:

  • Can someone from The Verge explain what exactly happened?
  • Was there a breach of account security somewhere?
  • Was it an isolated incident?
  • Should we change our account passwords?
I remember Gawker being compromised and they had to ask their users/commenters to change their passwords.