NEW YORK (AP) — Mark Zuckerberg says his "personal challenge" for 2018 is to fix Facebook.

The Facebook CEO has declared a goal each year since 2009. Past challenges have included wearing a tie every day, learning to speak Mandarin and eating meat only from animals he killed himself. Last year, he visited every U.S. state he hadn't been to yet.

This year, though, his challenge is directed at his company rather than personal ambitions. Zuckerberg wrote Thursday that he wants to focus this year on protecting Facebook users from abuse, defending against interference by nation-states and "making s...