Perez Hilton has made a name for himself by mocking and sensationalizing personal, and often intimate, issues in celebrities' lives. The Times calls it being in the business of "the demolition of celebrity reputations," and his past behavior pretty much lines up with that description.
He's famously attacked Lindsay Lohan during her battle with alcoholism, made fun of Nicole Richie's weight saying that she was just doing it for the attention, and nicknamed Amy Winehouse "Crackhouse" mere months before her death.
As his actions come under even more fire following the conservatorship battle with Britney Spears and her father, he says that he doesn't expect anyone to forgive him for all of the callous, and often offensive, things he's said and written.