It's a huge figure, If WhatsApp went for over $19 billion,then,Twitter should go beyond the $100 billion mark. Anything below 100 billions USD is a bad sell out! He can reconsider his shares if he likes or go build his own Twitter if he so much wants a free public speech. I think that Jack won't give him that power he's looking for in other tech space. Jack has done wonderfully well with Twitter though.