(CNN) -- The latest celebrity Twitter feud erupted Sunday between two heavyweights of the social medium. In one corner: pop superstar Lady Gaga and her nearly 40 million followers. In the other: pop culture blogger Perez Hilton and his 6.1 million Twitter fans. Who won the war of 140 characters? It depends on whom you ask. The feud between the former friends appears to stem from several incidents: Hilton tweeted Thursday that Katy Perry's new single, "Roar," is better than Gaga's latest song, "Applause." On Friday, Gaga, who is in the midst of a comeback following a serious tear to her right hip, cryptically referenced a text from Hilton that appeared to make light of her injury. "Still have the text Perez sent me of me in a wheelchair with the words KARMA written across + Madonna pointing a gun at me," she tweeted.
@highlight
Lady Gaga accuses the blogger of stalking her after he house-hunts at her NYC building
@highlight
Hilton says he learned later that her building was among those he looked at Sunday
@highlight
The former friends have not said why they had a falling out
But Gaga went into Twitter overdrive Sunday, accusing Hilton of stalking her, after one of her followers alerted her that he was at @placeholder's apartment building in New York.