Justin Timberlake was Sunday's Super Bowl halftime performer in Minneapolis.
His appearance was controversial due to his last halftime performance in 2004, with Janet Jackson. Jackson's top came off and her breast was revealed, while Timberlake sang the line "Bet I'll have you naked by the end of this song" from "Rock Your Body."
It was later deemed a "wardrobe malfunction."
Many people feel that the incident — dubbed Nipplegate — derailed Jackson's career, while Timberlake faced no consequences and never apologized.
Even before Sunday night's performance, Twitter declared it "Janet Jackson Appreciation Day," which many took as shade aimed toward Timberlake.