Best Celebrity Instagram and Twitter Pictures September 2012

September has flown by, so we're taking a comprehensive look back at some of the month's most memorable candid photos! Your favorite celebrities to follow on Instagram, Twitter, and Facebook, like Jennifer Lopez, Pink, Jessica Alba, and Ian Somerhalder, took to their favorite social media sharing sites to post personal photos from the set, on the road, Fashion Week, and hanging out at home with family and friends.

Click through to see our favorite photos, and don't forget to follow us on Instagram and Twitter for exciting news and photos.