Facebook founder and CEO Mark Zuckerberg is reported to be building a panic bunker next to his home in Palo Alto, California after a series of recent security upgrades.

Zuckerberg bought four surrounding houses to his $7 million mansion and has started the process of tearing one down in order to make way for security additions detailed in a recently submitted plan to the Palo Alto planning department.

According to the plans, Zuckerberg’s panic bunker is described as having “white brick walls, dark steel doors and windows, dark gray siding and louvers where they occur above the roof line, and a dark gray standing seam metal roof,” giving the impression of a steel fortress for the Facebook CEO to hide in if necessary.

Zuckerberg’s compound already has a perimeter of black panel walls in an attempt to stop both trespassers and snoopers. The Facebook CEO was slammed on social media after criticizing Donald Trump’s Mexican border wall plans and then returning to his fortressed mansion.

In April it was revealed that Zuckerberg had also spent $16 million on armed security guards at his mansion, while banning private gun sales on Facebook for the general public.

Facebook COO Sheryl Sandberg also spent $1.25 million on security last year.