Are modified tweets just plagiarism?

Jeb Lund has a contrarian view of journalism on Twitter. Lund argues that aggregating tweets and even just using the "MT" tag amount to theft of intellectual property: "For a profession enamored of examining how the sausage gets made – via gossip and high-mindedness – few people want to address whether a large part of that process, when it comes to Twitter, is theft. Appropriation, lifting, bigfooting, whatever you want to call it – it happens on scales large and small."