In 2017, it cost Facebook (FB) a whopping $7,326,640 to protect its chief, up from $4,891,441 the year before. According to a filing with the Securities and Exchange Commission (SEC) last week, this amount covered Zuckerberg’s protection at home and while traveling.

Why so much to protect Zuck in 2017? According to Facebook: “Specific threats to his safety arising directly as a result of his position as our founder, chairman and CEO.”

The filing continues:

We require these security measures for the company’s benefit because of the importance of Mr. Zuckerberg to Facebook, and we believe that the costs of this overall security program are appropriate and necessary. We paid for the initial procurement, installation, and maintenance of security measures for Mr. Zuckerberg’s personal residences, and we pay for the annual costs of security personnel. In addition, Mr. Zuckerberg uses private aircraft for personal travel in connection with his overall security program.

Facebook also paid $2,687,643 in 2017 for the personal security of its chief operating office, Sheryl Sandberg. This is roughly in line with her security costs in 2016.

These are huge figures, even in comparison with the security costs of comparable executives. For example, last year Amazon reported that it paid $1.6 million for the personal security of CEO Jeff Bezos in 2016—around the same as it paid in 2015.

The “board intelligence solutions” company Equilar said Bezos received the highest personal and home security perquisite of any Fortune 100 executive in 2015.

In case you’re wondering why Zuckerberg didn’t top him, that’s because Facebook does not classify Zuckerberg’s security program as a perquisite for his benefit.