Paparazzi photos from Thursday, September 2

Katie Cassidy watching Rafael Nadal's opening match at the US Open at Arthur Ashe Stadium in New York (pics start here)

Carmen Electra leaving the Viper Room in West Hollywood (pics start here)

Cindy Margolis at OK! magazine's 5th anniversary party at La Vida nightclub in Hollywood (pics start here)

Katy Perry arriving at BBC Radio 1 Studios in London (pics start here)

Rihanna arriving at her hotel in Oahu, Hawaii (pics start here)

Malin Akerman leaving the Viper Room in West Hollywood (pics start here)

Jon Hamm on the set of Mad Men at a hotel in Santa Monica (pics start here)

Alexa Chung arriving at Studio Valbone nightclub in London (pics start here)

Naomi Campbell and her boyfriend Vladislav Doronin at the premiere of Mirial at the 67th Venice Film Festival (pics start here)

Selena Gomez leaving Red O restaurant in West Hollywood (pics start here)

Karolina Kurkova out and about in New York (pics start here)

Sienna Miller leaving Soho House in London (pics start here)

*163 paparazzi pictures total in the gallery:

[Flynet, WENN, Pacific Coast News, Mavrixonline]