At the end of a critical week for Facebook, one that included more than 10 hours of testimony on Capitol Hill by CEO Mark Zuckerberg about issues such as user privacy and data security, the company disclosed what it spent on a different kind of security: Its CEO's.

In a document filed late Friday, Facebook said it had spent $7.3 million in personal security costs and $1.5 million on personal use of private aircraft by Zuckerberg in 2017, a 54 percent increase from the year before, bringing the total to $8.8 million, compared with $5.8 million in 2016.