Celebrities including Jessica Biel, Kristen Bell and Austin Mahone all came together this evening for Think It Up, a fundraiser aimed to support education.

Zuckerberg explains his latest book-club pick on his personal Facebook page:It's mind-blowing that almost half the world — almost 3 billion people — live on $2.50 a day or less. More than one billion people live on $1 a day or less.

Some elements of this video from Denmark-based digital agency Inetdesign seem awfully familiar.That's because the clip uses famous logos to explain the importance of branding.

Over a year ago, icy water inundated the Internet in what may have been the online equivalent of the largest chain letter ever—the ALS Ice Bucket Challenge. In endless Facebook videos, people hoisted buckets filled with ice water, announced their philanthropic intentions, and upended the buckets over their heads.