The hashtag "50 in 07" was originally created by the twitter account @DanyAllstar15 who is a parody account of the NHL player Dany Heatley. The hashtag refers to Heatley's 50 goal season he had back in 2007. The account mostly just makes fun of other members that are part of the NHL or anyone in other current sport events such as the World Cup right now. Here is an example of a tweet from his account involving LeBron James who recently lost his chance at winning the NBA finals: "Yeah, LeBron didn't have 50 in '07 and he also just lost in the championships which is cool." This isn't an example of one of his best tweets but it was also one of the few clean ones. He also has many funny edits of pictures that illustrate Dany Heatley as being better than everybody else.
Overall, the hashtag "50 in 07" not only demonstrates the impressive milestone that Dany Heatley Reached in 2007 but also the allstar that he is as a whole.