It appears that yesterdays ruckus with TweetDeck was caused by a 19-year-old Austrian teenager that found that typing hearts creates a heart symbol in HTML. Named Florian, the teen discovered that this created a door in TweetDeck that allowed injection of commands via a tweet. It wasn’t a hack. It was some sort of accident, he told CNN via Twitter. Florian then tinkered for a while by adding a heart to every message causing a pop-up window in his TweetDe…