Vitalii Sediuk posted online that he wanted to encourage the Kardashian family to promote "natural beauty" to the teenage girls who follow them "blindly".
He has targeted many celebrities including Gigi Hadid and Leonardo DiCaprio.
Some claim his "pranks" are "sleazy".
While in Paris on Wednesday, a man approached Kim Kardashian.
He tried to grab her leg and kiss her bottom, but was quickly stopped by one of her bodyguards.
Soon after, Vitalii Sediuk explained his reasons for the stunt.